Merge tag 'tty-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of TTY and Serial driver updates for 6.1-rc1.

  Lots of cleanups in here, no real new functionality this time around,
  with the diffstat being that we removed more lines than we added!

  Included in here are:

   - termios unification cleanups from Al Viro, it's nice to finally get
     this work done

   - tty serial transmit cleanups in various drivers in preparation for
     more cleanup and unification in future releases (that work was not
     ready for this release)

   - n_gsm fixes and updates

   - ktermios cleanups and code reductions

   - dt bindings json conversions and updates for new devices

   - some serial driver updates for new devices

   - lots of other tiny cleanups and janitorial stuff. Full details in
     the shortlog.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (102 commits)
  serial: cpm_uart: Don't request IRQ too early for console port
  tty: serial: do unlock on a common path in altera_jtaguart_console_putc()
  tty: serial: unify TX space reads under altera_jtaguart_tx_space()
  tty: serial: use FIELD_GET() in lqasc_tx_ready()
  tty: serial: extend lqasc_tx_ready() to lqasc_console_putchar()
  tty: serial: allow pxa.c to be COMPILE_TESTed
  serial: stm32: Fix unused-variable warning
  tty: serial: atmel: Add COMMON_CLK dependency to SERIAL_ATMEL
  serial: 8250: Fix restoring termios speed after suspend
  serial: Deassert Transmit Enable on probe in driver-specific way
  serial: 8250_dma: Convert to use uart_xmit_advance()
  serial: 8250_omap: Convert to use uart_xmit_advance()
  MAINTAINERS: Solve warning regarding inexistent atmel-usart binding
  serial: stm32: Deassert Transmit Enable on ->rs485_config()
  serial: ar933x: Deassert Transmit Enable on ->rs485_config()
  tty: serial: atmel: Use FIELD_PREP/FIELD_GET
  tty: serial: atmel: Make the driver aware of the existence of GCLK
  tty: serial: atmel: Only divide Clock Divisor if the IP is USART
  tty: serial: atmel: Separate mode clearing between UART and USART
  dt-bindings: serial: atmel,at91-usart: Add gclk as a possible USART clock
  ...

145 files changed, 968 insertions, 771 deletions

diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index 8fc49b038372..b2735be81ab2 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -2274,7 +2274,8 @@ static int mgslpc_ioctl(struct tty_struct *tty,
  *	tty		pointer to tty structure
  *	termios		pointer to buffer to hold returned old termios
  */
-static void mgslpc_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
+static void mgslpc_set_termios(struct tty_struct *tty,
+			       const struct ktermios *old_termios)
 {
 	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
 	unsigned long flags;
diff --git a/drivers/ipack/devices/ipoctal.c b/drivers/ipack/devices/ipoctal.c
index 20d2b9ec1227..fc00274070b6 100644
--- a/drivers/ipack/devices/ipoctal.c
+++ b/drivers/ipack/devices/ipoctal.c
@@ -497,7 +497,7 @@ static unsigned int ipoctal_chars_in_buffer(struct tty_struct *tty)
 }
 
 static void ipoctal_set_termios(struct tty_struct *tty,
-				struct ktermios *old_termios)
+				const struct ktermios *old_termios)
 {
 	unsigned int cflag;
 	unsigned char mr1 = 0;
diff --git a/drivers/mmc/core/sdio_uart.c b/drivers/mmc/core/sdio_uart.c
index 414aa82abc39..ae7ef2e038be 100644
--- a/drivers/mmc/core/sdio_uart.c
+++ b/drivers/mmc/core/sdio_uart.c
@@ -246,7 +246,7 @@ static inline void sdio_uart_update_mctrl(struct sdio_uart_port *port,
 
 static void sdio_uart_change_speed(struct sdio_uart_port *port,
 				   struct ktermios *termios,
-				   struct ktermios *old)
+				   const struct ktermios *old)
 {
 	unsigned char cval, fcr = 0;
 	unsigned int baud, quot;
@@ -859,7 +859,7 @@ static void sdio_uart_unthrottle(struct tty_struct *tty)
 }
 
 static void sdio_uart_set_termios(struct tty_struct *tty,
-						struct ktermios *old_termios)
+				  const struct ktermios *old_termios)
 {
 	struct sdio_uart_port *port = tty->driver_data;
 	unsigned int cflag = tty->termios.c_cflag;
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index f8221a7acf62..ce1f6081d582 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -1380,7 +1380,8 @@ static void hso_serial_cleanup(struct tty_struct *tty)
 }
 
 /* setup the term */
-static void hso_serial_set_termios(struct tty_struct *tty, struct ktermios *old)
+static void hso_serial_set_termios(struct tty_struct *tty,
+				   const struct ktermios *old)
 {
 	struct hso_serial *serial = tty->driver_data;
 	unsigned long flags;
diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c
index b8c7843730ed..62e9f7d6c9fe 100644
--- a/drivers/net/wwan/wwan_core.c
+++ b/drivers/net/wwan/wwan_core.c
@@ -13,6 +13,7 @@
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <linux/uaccess.h>
 #include <linux/termios.h>
 #include <linux/wwan.h>
 #include <net/rtnetlink.h>
diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
index 5c83f71c1d0e..26e3995ac062 100644
--- a/drivers/s390/char/tty3270.c
+++ b/drivers/s390/char/tty3270.c
@@ -1760,7 +1760,7 @@ tty3270_flush_chars(struct tty_struct *tty)
  * Check for visible/invisible input switches
  */
 static void
-tty3270_set_termios(struct tty_struct *tty, struct ktermios *old)
+tty3270_set_termios(struct tty_struct *tty, const struct ktermios *old)
 {
 	struct tty3270 *tp;
 	int new;
diff --git a/drivers/staging/fwserial/fwserial.c b/drivers/staging/fwserial/fwserial.c
index e8fa7f53cd5e..81b06d88ed0d 100644
--- a/drivers/staging/fwserial/fwserial.c
+++ b/drivers/staging/fwserial/fwserial.c
@@ -1267,7 +1267,8 @@ static int fwtty_ioctl(struct tty_struct *tty, unsigned int cmd,
 	return err;
 }
 
-static void fwtty_set_termios(struct tty_struct *tty, struct ktermios *old)
+static void fwtty_set_termios(struct tty_struct *tty,
+			      const struct ktermios *old)
 {
 	struct fwtty_port *port = tty->driver_data;
 	unsigned int baud;
diff --git a/drivers/staging/greybus/uart.c b/drivers/staging/greybus/uart.c
index dc4ed0ff1ae2..90ff07f2cbf7 100644
--- a/drivers/staging/greybus/uart.c
+++ b/drivers/staging/greybus/uart.c
@@ -480,7 +480,7 @@ static int gb_tty_break_ctl(struct tty_struct *tty, int state)
 }
 
 static void gb_tty_set_termios(struct tty_struct *tty,
-			       struct ktermios *termios_old)
+			       const struct ktermios *termios_old)
 {
 	struct gb_uart_set_line_coding_request newline;
 	struct gb_tty *gb_tty = tty->driver_data;
diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index 81e7f64c1739..f52266766df9 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -94,7 +94,7 @@ static struct tty_driver *serial_driver;
 static unsigned char current_ctl_bits;
 
 static void change_speed(struct tty_struct *tty, struct serial_state *info,
-		struct ktermios *old);
+			 const struct ktermios *old);
 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
 
 
@@ -566,7 +566,7 @@ static void shutdown(struct tty_struct *tty, struct serial_state *info)
  * the specified baud rate for a serial port.
  */
 static void change_speed(struct tty_struct *tty, struct serial_state *info,
-			 struct ktermios *old_termios)
+			 const struct ktermios *old_termios)
 {
 	struct tty_port *port = &info->tport;
 	int	quot = 0, baud_base, baud;
@@ -1169,7 +1169,7 @@ static int rs_ioctl(struct tty_struct *tty,
 	return 0;
 }
 
-static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
+static void rs_set_termios(struct tty_struct *tty, const struct ktermios *old_termios)
 {
 	struct serial_state *info = tty->driver_data;
 	unsigned long flags;
diff --git a/drivers/tty/hvc/hvc_iucv.c b/drivers/tty/hvc/hvc_iucv.c
index 32366caca662..7d49a872de48 100644
--- a/drivers/tty/hvc/hvc_iucv.c
+++ b/drivers/tty/hvc/hvc_iucv.c
@@ -29,7 +29,6 @@
 
 
 /* General device driver settings */
-#define HVC_IUCV_MAGIC		0xc9e4c3e5
 #define MAX_HVC_IUCV_LINES	HVC_ALLOC_TTY_ADAPTERS
 #define MEMPOOL_MIN_NR		(PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4)
 
@@ -131,9 +130,9 @@ static struct iucv_handler hvc_iucv_handler = {
  */
 static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num)
 {
-	if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices))
+	if (num > hvc_iucv_devices)
 		return NULL;
-	return hvc_iucv_table[num - HVC_IUCV_MAGIC];
+	return hvc_iucv_table[num];
 }
 
 /**
@@ -1072,8 +1071,8 @@ static int __init hvc_iucv_alloc(int id, unsigned int is_console)
 	priv->is_console = is_console;
 
 	/* allocate hvc device */
-	priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /*		  PAGE_SIZE */
-			      HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256);
+	priv->hvc = hvc_alloc(id, /*		 PAGE_SIZE */
+			      id, &hvc_iucv_ops, 256);
 	if (IS_ERR(priv->hvc)) {
 		rc = PTR_ERR(priv->hvc);
 		goto out_error_hvc;
@@ -1371,7 +1370,7 @@ static int __init hvc_iucv_init(void)
 
 	/* register the first terminal device as console
 	 * (must be done before allocating hvc terminal devices) */
-	rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops);
+	rc = hvc_instantiate(0, IUCV_HVC_CON_IDX, &hvc_iucv_ops);
 	if (rc) {
 		pr_err("Registering HVC terminal device as "
 		       "Linux console failed\n");
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 9b7e8246a464..4ba24963685e 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -69,6 +69,7 @@
 #include <asm/hvconsole.h>
 #include <asm/hvcserver.h>
 #include <linux/uaccess.h>
+#include <linux/termios_internal.h>
 #include <asm/vio.h>
 
 /*
@@ -839,7 +840,7 @@ static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd)
 	hvcsd->p_partition_ID  = pi->partition_ID;
 
 	/* copy the null-term char too */
-	strlcpy(hvcsd->p_location_code, pi->location_code,
+	strscpy(hvcsd->p_location_code, pi->location_code,
 		sizeof(hvcsd->p_location_code));
 }
 
diff --git a/drivers/tty/moxa.c b/drivers/tty/moxa.c
index f3c72ab1476c..35b6fddf0341 100644
--- a/drivers/tty/moxa.c
+++ b/drivers/tty/moxa.c
@@ -491,7 +491,7 @@ static int moxa_write(struct tty_struct *, const unsigned char *, int);
 static unsigned int moxa_write_room(struct tty_struct *);
 static void moxa_flush_buffer(struct tty_struct *);
 static unsigned int moxa_chars_in_buffer(struct tty_struct *);
-static void moxa_set_termios(struct tty_struct *, struct ktermios *);
+static void moxa_set_termios(struct tty_struct *, const struct ktermios *);
 static void moxa_stop(struct tty_struct *);
 static void moxa_start(struct tty_struct *);
 static void moxa_hangup(struct tty_struct *);
@@ -499,7 +499,7 @@ static int moxa_tiocmget(struct tty_struct *tty);
 static int moxa_tiocmset(struct tty_struct *tty,
 			 unsigned int set, unsigned int clear);
 static void moxa_poll(struct timer_list *);
-static void moxa_set_tty_param(struct tty_struct *, struct ktermios *);
+static void moxa_set_tty_param(struct tty_struct *, const struct ktermios *);
 static void moxa_shutdown(struct tty_port *);
 static int moxa_carrier_raised(struct tty_port *);
 static void moxa_dtr_rts(struct tty_port *, int);
@@ -1602,7 +1602,7 @@ static int moxa_tiocmset(struct tty_struct *tty,
 }
 
 static void moxa_set_termios(struct tty_struct *tty,
-		struct ktermios *old_termios)
+		             const struct ktermios *old_termios)
 {
 	struct moxa_port *ch = tty->driver_data;
 
@@ -1761,7 +1761,8 @@ static void moxa_poll(struct timer_list *unused)
 
 /******************************************************************************/
 
-static void moxa_set_tty_param(struct tty_struct *tty, struct ktermios *old_termios)
+static void moxa_set_tty_param(struct tty_struct *tty,
+			       const struct ktermios *old_termios)
 {
 	register struct ktermios *ts = &tty->termios;
 	struct moxa_port *ch = tty->driver_data;
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 70b982b2c6b2..2436e0b10f9a 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -398,7 +398,7 @@ static enum mxser_must_hwid mxser_must_get_hwid(unsigned long io)
 	oldmcr = inb(io + UART_MCR);
 	outb(0, io + UART_MCR);
 	mxser_set_must_xon1_value(io, 0x11);
-	if ((hwid = inb(io + UART_MCR)) != 0) {
+	if (inb(io + UART_MCR) != 0) {
 		outb(oldmcr, io + UART_MCR);
 		return MOXA_OTHER_UART;
 	}
@@ -571,7 +571,8 @@ static void mxser_handle_cts(struct tty_struct *tty, struct mxser_port *info,
  * This routine is called to set the UART divisor registers to match
  * the specified baud rate for a serial port.
  */
-static void mxser_change_speed(struct tty_struct *tty, struct ktermios *old_termios)
+static void mxser_change_speed(struct tty_struct *tty,
+			       const struct ktermios *old_termios)
 {
 	struct mxser_port *info = tty->driver_data;
 	unsigned cflag, cval;
@@ -1348,7 +1349,8 @@ static void mxser_start(struct tty_struct *tty)
 	spin_unlock_irqrestore(&info->slock, flags);
 }
 
-static void mxser_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
+static void mxser_set_termios(struct tty_struct *tty,
+			      const struct ktermios *old_termios)
 {
 	struct mxser_port *info = tty->driver_data;
 	unsigned long flags;
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 01c112e2e214..5e516f5cac5a 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -63,6 +63,14 @@
 static int debug;
 module_param(debug, int, 0600);
 
+/* Module debug bits */
+#define DBG_DUMP	BIT(0) /* Data transmission dump. */
+#define DBG_CD_ON	BIT(1) /* Always assume CD line on. */
+#define DBG_DATA	BIT(2) /* Data transmission details. */
+#define DBG_ERRORS	BIT(3) /* Details for fail conditions. */
+#define DBG_TTY		BIT(4) /* Transmission statistics for DLCI TTYs. */
+#define DBG_PAYLOAD	BIT(5) /* Limits DBG_DUMP to payload frames. */
+
 /* Defaults: these are from the specification */
 
 #define T1	10		/* 100mS */
@@ -164,6 +172,9 @@ struct gsm_dlci {
 	struct net_device *net; /* network interface, if created */
 };
 
+/* Total number of supported devices */
+#define GSM_TTY_MINORS		256
+
 /* DLCI 0, 62/63 are special or reserved see gsmtty_open */
 
 #define NUM_DLCI		64
@@ -184,6 +195,11 @@ struct gsm_control {
 	int error;	/* Error if any */
 };
 
+enum gsm_encoding {
+	GSM_BASIC_OPT,
+	GSM_ADV_OPT,
+};
+
 enum gsm_mux_state {
 	GSM_SEARCH,
 	GSM_START,
@@ -230,7 +246,7 @@ struct gsm_mux {
 	unsigned int address;
 	unsigned int count;
 	bool escape;
-	int encoding;
+	enum gsm_encoding encoding;
 	u8 control;
 	u8 fcs;
 	u8 *txframe;			/* TX framing buffer */
@@ -527,7 +543,7 @@ static int gsm_register_devices(struct tty_driver *driver, unsigned int index)
 		 */
 		dev = tty_register_device(gsm_tty_driver, base + i, NULL);
 		if (IS_ERR(dev)) {
-			if (debug & 8)
+			if (debug & DBG_ERRORS)
 				pr_info("%s failed to register device minor %u",
 					__func__, base + i);
 			for (i--; i >= 1; i--)
@@ -581,8 +597,12 @@ static void gsm_unregister_devices(struct tty_driver *driver,
 static void gsm_print_packet(const char *hdr, int addr, int cr,
 					u8 control, const u8 *data, int dlen)
 {
-	if (!(debug & 1))
+	if (!(debug & DBG_DUMP))
 		return;
+	/* Only show user payload frames if debug & DBG_PAYLOAD */
+	if (!(debug & DBG_PAYLOAD) && addr != 0)
+		if ((control & ~PF) == UI || (control & ~PF) == UIH)
+			return;
 
 	pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]);
 
@@ -693,7 +713,7 @@ static int gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
 	*dp++ = (addr << 2) | (ocr << 1) | EA;
 	*dp++ = control;
 
-	if (gsm->encoding == 0)
+	if (gsm->encoding == GSM_BASIC_OPT)
 		*dp++ = EA; /* Length of data = 0 */
 
 	*dp = 0xFF - gsm_fcs_add_block(INIT_FCS, msg->data, dp - msg->data);
@@ -812,7 +832,7 @@ static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg)
 	int len, ret;
 
 
-	if (gsm->encoding == 0) {
+	if (gsm->encoding == GSM_BASIC_OPT) {
 		gsm->txframe[0] = GSM0_SOF;
 		memcpy(gsm->txframe + 1, msg->data, msg->len);
 		gsm->txframe[msg->len + 1] = GSM0_SOF;
@@ -824,7 +844,7 @@ static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg)
 		len += 2;
 	}
 
-	if (debug & 4)
+	if (debug & DBG_DATA)
 		gsm_hex_dump_bytes(__func__, gsm->txframe, len);
 	gsm_print_packet("-->", msg->addr, gsm->initiator, msg->ctrl, msg->data,
 			 msg->len);
@@ -964,7 +984,7 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
 	u8 *fcs = dp + msg->len;
 
 	/* Fill in the header */
-	if (gsm->encoding == 0) {
+	if (gsm->encoding == GSM_BASIC_OPT) {
 		if (msg->len < 128)
 			*--dp = (msg->len << 1) | EA;
 		else {
@@ -1306,6 +1326,31 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
 
 
 /**
+ * gsm_control_command	-	send a command frame to a control
+ * @gsm: gsm channel
+ * @cmd: the command to use
+ * @data: data to follow encoded info
+ * @dlen: length of data
+ *
+ * Encode up and queue a UI/UIH frame containing our command.
+ */
+static int gsm_control_command(struct gsm_mux *gsm, int cmd, const u8 *data,
+			       int dlen)
+{
+	struct gsm_msg *msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype);
+
+	if (msg == NULL)
+		return -ENOMEM;
+
+	msg->data[0] = (cmd << 1) | CR | EA;	/* Set C/R */
+	msg->data[1] = (dlen << 1) | EA;
+	memcpy(msg->data + 2, data, dlen);
+	gsm_data_queue(gsm->dlci[0], msg);
+
+	return 0;
+}
+
+/**
  *	gsm_control_reply	-	send a response frame to a control
  *	@gsm: gsm channel
  *	@cmd: the command to use
@@ -1407,18 +1452,12 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen)
 	unsigned int modem = 0;
 	struct gsm_dlci *dlci;
 	int len = clen;
-	int slen;
+	int cl = clen;
 	const u8 *dp = data;
 	struct tty_struct *tty;
 
-	while (gsm_read_ea(&addr, *dp++) == 0) {
-		len--;
-		if (len == 0)
-			return;
-	}
-	/* Must be at least one byte following the EA */
-	len--;
-	if (len <= 0)
+	len = gsm_read_ea_val(&addr, data, cl);
+	if (len < 1)
 		return;
 
 	addr >>= 1;
@@ -1427,15 +1466,20 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen)
 		return;
 	dlci = gsm->dlci[addr];
 
-	slen = len;
-	while (gsm_read_ea(&modem, *dp++) == 0) {
-		len--;
-		if (len == 0)
-			return;
-	}
-	len--;
+	/* Must be at least one byte following the EA */
+	if ((cl - len) < 1)
+		return;
+
+	dp += len;
+	cl -= len;
+
+	/* get the modem status */
+	len = gsm_read_ea_val(&modem, dp, cl);
+	if (len < 1)
+		return;
+
 	tty = tty_port_tty_get(&dlci->port);
-	gsm_process_modem(tty, dlci, modem, slen - len);
+	gsm_process_modem(tty, dlci, modem, cl);
 	if (tty) {
 		tty_wakeup(tty);
 		tty_kref_put(tty);
@@ -1611,13 +1655,7 @@ static void gsm_control_response(struct gsm_mux *gsm, unsigned int command,
 
 static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl)
 {
-	struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 2, gsm->ftype);
-	if (msg == NULL)
-		return;
-	msg->data[0] = (ctrl->cmd << 1) | CR | EA;	/* command */
-	msg->data[1] = (ctrl->len << 1) | EA;
-	memcpy(msg->data + 2, ctrl->data, ctrl->len);
-	gsm_data_queue(gsm->dlci[0], msg);
+	gsm_control_command(gsm, ctrl->cmd, ctrl->data, ctrl->len);
 }
 
 /**
@@ -1737,7 +1775,7 @@ static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control)
 static void gsm_dlci_close(struct gsm_dlci *dlci)
 {
 	del_timer(&dlci->t1);
-	if (debug & 8)
+	if (debug & DBG_ERRORS)
 		pr_debug("DLCI %d goes closed.\n", dlci->addr);
 	dlci->state = DLCI_CLOSED;
 	/* Prevent us from sending data before the link is up again */
@@ -1771,7 +1809,7 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
 	/* This will let a tty open continue */
 	dlci->state = DLCI_OPEN;
 	dlci->constipated = false;
-	if (debug & 8)
+	if (debug & DBG_ERRORS)
 		pr_debug("DLCI %d goes open.\n", dlci->addr);
 	/* Send current modem state */
 	if (dlci->addr)
@@ -1807,7 +1845,7 @@ static void gsm_dlci_t1(struct timer_list *t)
 			gsm_command(dlci->gsm, dlci->addr, SABM|PF);
 			mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
 		} else if (!dlci->addr && gsm->control == (DM | PF)) {
-			if (debug & 8)
+			if (debug & DBG_ERRORS)
 				pr_info("DLCI %d opening in ADM mode.\n",
 					dlci->addr);
 			dlci->mode = DLCI_MODE_ADM;
@@ -1910,11 +1948,10 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen)
 	struct tty_port *port = &dlci->port;
 	struct tty_struct *tty;
 	unsigned int modem = 0;
-	int len = clen;
-	int slen = 0;
+	int len;
 
-	if (debug & 16)
-		pr_debug("%d bytes for tty\n", len);
+	if (debug & DBG_TTY)
+		pr_debug("%d bytes for tty\n", clen);
 	switch (dlci->adaption)  {
 	/* Unsupported types */
 	case 4:		/* Packetised interruptible data */
@@ -1922,24 +1959,22 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen)
 	case 3:		/* Packetised uininterruptible voice/data */
 		break;
 	case 2:		/* Asynchronous serial with line state in each frame */
-		while (gsm_read_ea(&modem, *data++) == 0) {
-			len--;
-			slen++;
-			if (len == 0)
-				return;
-		}
-		len--;
-		slen++;
+		len = gsm_read_ea_val(&modem, data, clen);
+		if (len < 1)
+			return;
 		tty = tty_port_tty_get(port);
 		if (tty) {
-			gsm_process_modem(tty, dlci, modem, slen);
+			gsm_process_modem(tty, dlci, modem, len);
 			tty_wakeup(tty);
 			tty_kref_put(tty);
 		}
+		/* Skip processed modem data */
+		data += len;
+		clen -= len;
 		fallthrough;
 	case 1:		/* Line state will go via DLCI 0 controls only */
 	default:
-		tty_insert_flip_string(port, data, len);
+		tty_insert_flip_string(port, data, clen);
 		tty_flip_buffer_push(port);
 	}
 }
@@ -1960,24 +1995,27 @@ static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len)
 {
 	/* See what command is involved */
 	unsigned int command = 0;
-	while (len-- > 0) {
-		if (gsm_read_ea(&command, *data++) == 1) {
-			int clen = *data++;
-			len--;
-			/* FIXME: this is properly an EA */
-			clen >>= 1;
-			/* Malformed command ? */
-			if (clen > len)
-				return;
-			if (command & 1)
-				gsm_control_message(dlci->gsm, command,
-								data, clen);
-			else
-				gsm_control_response(dlci->gsm, command,
-								data, clen);
-			return;
-		}
-	}
+	unsigned int clen = 0;
+	unsigned int dlen;
+
+	/* read the command */
+	dlen = gsm_read_ea_val(&command, data, len);
+	len -= dlen;
+	data += dlen;
+
+	/* read any control data */
+	dlen = gsm_read_ea_val(&clen, data, len);
+	len -= dlen;
+	data += dlen;
+
+	/* Malformed command? */
+	if (clen > len)
+		return;
+
+	if (command & 1)
+		gsm_control_message(dlci->gsm, command, data, clen);
+	else
+		gsm_control_response(dlci->gsm, command, data, clen);
 }
 
 /**
@@ -1999,7 +2037,7 @@ static void gsm_kick_timeout(struct work_struct *work)
 		sent = gsm_dlci_data_sweep(gsm);
 	mutex_unlock(&gsm->tx_mutex);
 
-	if (sent && debug & 4)
+	if (sent && debug & DBG_DATA)
 		pr_info("%s TX queue stalled\n", __func__);
 }
 
@@ -2133,7 +2171,7 @@ static void gsm_queue(struct gsm_mux *gsm)
 
 	if (gsm->fcs != GOOD_FCS) {
 		gsm->bad_fcs++;
-		if (debug & 4)
+		if (debug & DBG_DATA)
 			pr_debug("BAD FCS %02x\n", gsm->fcs);
 		return;
 	}
@@ -2497,7 +2535,7 @@ static int gsm_activate_mux(struct gsm_mux *gsm)
 	if (dlci == NULL)
 		return -ENOMEM;
 
-	if (gsm->encoding == 0)
+	if (gsm->encoding == GSM_BASIC_OPT)
 		gsm->receive = gsm0_receive;
 	else
 		gsm->receive = gsm1_receive;
@@ -2614,7 +2652,7 @@ static struct gsm_mux *gsm_alloc_mux(void)
 	gsm->n2 = N2;
 	gsm->ftype = UIH;
 	gsm->adaption = 1;
-	gsm->encoding = 1;
+	gsm->encoding = GSM_ADV_OPT;
 	gsm->mru = 64;	/* Default to encoding 1 so these should be 64 */
 	gsm->mtu = 64;
 	gsm->dead = true;	/* Avoid early tty opens */
@@ -2716,7 +2754,7 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c)
 	gsm->initiator = c->initiator;
 	gsm->mru = c->mru;
 	gsm->mtu = c->mtu;
-	gsm->encoding = c->encapsulation;
+	gsm->encoding = c->encapsulation ? GSM_ADV_OPT : GSM_BASIC_OPT;
 	gsm->adaption = c->adaption;
 	gsm->n2 = c->n2;
 
@@ -2760,7 +2798,7 @@ static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
 		set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags);
 		return -ENOSPC;
 	}
-	if (debug & 4)
+	if (debug & DBG_DATA)
 		gsm_hex_dump_bytes(__func__, data, len);
 	return gsm->tty->ops->write(gsm->tty, data, len);
 }
@@ -2846,7 +2884,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 	struct gsm_mux *gsm = tty->disc_data;
 	char flags = TTY_NORMAL;
 
-	if (debug & 4)
+	if (debug & DBG_DATA)
 		gsm_hex_dump_bytes(__func__, cp, count);
 
 	for (; count; count--, cp++) {
@@ -2939,8 +2977,7 @@ static int gsmld_open(struct tty_struct *tty)
 	tty->receive_room = 65536;
 
 	/* Attach the initial passive connection */
-	gsm->encoding = 1;
-
+	gsm->encoding = GSM_ADV_OPT;
 	gsmld_attach_gsm(tty, gsm);
 
 	return 0;
@@ -3336,7 +3373,7 @@ static int gsm_modem_upd_via_msc(struct gsm_dlci *dlci, u8 brk)
 	struct gsm_control *ctrl;
 	int len = 2;
 
-	if (dlci->gsm->encoding != 0)
+	if (dlci->gsm->encoding != GSM_BASIC_OPT)
 		return 0;
 
 	modembits[0] = (dlci->addr << 2) | 2 | EA;  /* DLCI, Valid, EA */
@@ -3365,7 +3402,7 @@ static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk)
 		/* Send convergence layer type 2 empty data frame. */
 		gsm_modem_upd_via_data(dlci, brk);
 		return 0;
-	} else if (dlci->gsm->encoding == 0) {
+	} else if (dlci->gsm->encoding == GSM_BASIC_OPT) {
 		/* Send as MSC control message. */
 		return gsm_modem_upd_via_msc(dlci, brk);
 	}
@@ -3382,15 +3419,15 @@ static int gsm_carrier_raised(struct tty_port *port)
 	/* Not yet open so no carrier info */
 	if (dlci->state != DLCI_OPEN)
 		return 0;
-	if (debug & 2)
+	if (debug & DBG_CD_ON)
 		return 1;
 
 	/*
 	 * Basic mode with control channel in ADM mode may not respond
 	 * to CMD_MSC at all and modem_rx is empty.
 	 */
-	if (gsm->encoding == 0 && gsm->dlci[0]->mode == DLCI_MODE_ADM &&
-	    !dlci->modem_rx)
+	if (gsm->encoding == GSM_BASIC_OPT &&
+	    gsm->dlci[0]->mode == DLCI_MODE_ADM && !dlci->modem_rx)
 		return 1;
 
 	return dlci->modem_rx & TIOCM_CD;
@@ -3638,7 +3675,8 @@ static int gsmtty_ioctl(struct tty_struct *tty,
 	}
 }
 
-static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old)
+static void gsmtty_set_termios(struct tty_struct *tty,
+			       const struct ktermios *old)
 {
 	struct gsm_dlci *dlci = tty->driver_data;
 	if (dlci->state == DLCI_CLOSED)
@@ -3736,7 +3774,7 @@ static int __init gsm_init(void)
 		return status;
 	}
 
-	gsm_tty_driver = tty_alloc_driver(256, TTY_DRIVER_REAL_RAW |
+	gsm_tty_driver = tty_alloc_driver(GSM_TTY_MINORS, TTY_DRIVER_REAL_RAW |
 			TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_HARDWARE_BREAK);
 	if (IS_ERR(gsm_tty_driver)) {
 		pr_err("gsm_init: tty allocation failed.\n");
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 94c1ec2dd754..46b09bfb6f3a 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -76,8 +76,6 @@
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#define HDLC_MAGIC 0x239e
-
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -98,7 +96,6 @@
 #include <linux/if.h>
 #include <linux/bitops.h>
 
-#include <asm/termios.h>
 #include <linux/uaccess.h>
 #include "tty.h"
 
@@ -124,7 +121,6 @@ struct n_hdlc_buf_list {
 
 /**
  * struct n_hdlc - per device instance data structure
- * @magic: magic value for structure
  * @tbusy: reentrancy flag for tx wakeup code
  * @woke_up: tx wakeup needs to be run again as it was called while @tbusy
  * @tx_buf_list: list of pending transmit frame buffers
@@ -133,7 +129,6 @@ struct n_hdlc_buf_list {
  * @rx_free_buf_list: list unused received frame buffers
  */
 struct n_hdlc {
-	int			magic;
 	bool			tbusy;
 	bool			woke_up;
 	struct n_hdlc_buf_list	tx_buf_list;
@@ -200,10 +195,6 @@ static void n_hdlc_tty_close(struct tty_struct *tty)
 {
 	struct n_hdlc *n_hdlc = tty->disc_data;
 
-	if (n_hdlc->magic != HDLC_MAGIC) {
-		pr_warn("n_hdlc: trying to close unopened tty!\n");
-		return;
-	}
 #if defined(TTY_NO_WRITE_SPLIT)
 	clear_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
 #endif
@@ -386,12 +377,6 @@ static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data,
 
 	pr_debug("%s() called count=%d\n", __func__, count);
 
-	/* verify line is using HDLC discipline */
-	if (n_hdlc->magic != HDLC_MAGIC) {
-		pr_err("line not using HDLC discipline\n");
-		return;
-	}
-
 	if (count > maxframe) {
 		pr_debug("rx count>maxframesize, data discarded\n");
 		return;
@@ -542,9 +527,6 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
 
 	pr_debug("%s() called count=%zd\n", __func__, count);
 
-	if (n_hdlc->magic != HDLC_MAGIC)
-		return -EIO;
-
 	/* verify frame size */
 	if (count > maxframe) {
 		pr_debug("%s: truncating user packet from %zu to %d\n",
@@ -609,10 +591,6 @@ static int n_hdlc_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
 
 	pr_debug("%s() called %d\n", __func__, cmd);
 
-	/* Verify the status of the device */
-	if (n_hdlc->magic != HDLC_MAGIC)
-		return -EBADF;
-
 	switch (cmd) {
 	case FIONREAD:
 		/* report count of read data available */
@@ -673,9 +651,6 @@ static __poll_t n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
 	struct n_hdlc *n_hdlc = tty->disc_data;
 	__poll_t mask = 0;
 
-	if (n_hdlc->magic != HDLC_MAGIC)
-		return 0;
-
 	/*
 	 * queue the current process into any wait queue that may awaken in the
 	 * future (read and write)
@@ -739,9 +714,6 @@ static struct n_hdlc *n_hdlc_alloc(void)
 	n_hdlc_alloc_buf(&n_hdlc->rx_free_buf_list, DEFAULT_RX_BUF_COUNT, "rx");
 	n_hdlc_alloc_buf(&n_hdlc->tx_free_buf_list, DEFAULT_TX_BUF_COUNT, "tx");
 
-	/* Initialize the control block */
-	n_hdlc->magic  = HDLC_MAGIC;
-
 	return n_hdlc;
 
 }	/* end of n_hdlc_alloc() */
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 3afdd9033a9c..597019690ae6 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1758,7 +1758,7 @@ static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
  *
  * Locking: Caller holds @tty->termios_rwsem
  */
-static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
+static void n_tty_set_termios(struct tty_struct *tty, const struct ktermios *old)
 {
 	struct n_tty_data *ldata = tty->disc_data;
 
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 752dab3356d7..07394fdaf522 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -240,7 +240,7 @@ out:
 }
 
 static void pty_set_termios(struct tty_struct *tty,
-					struct ktermios *old_termios)
+			    const struct ktermios *old_termios)
 {
 	/* See if packet mode change of state. */
 	if (tty->link && tty->link->ctrl.packet) {
diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c
index 65d6af755567..c7d34823f715 100644
--- a/drivers/tty/serial/21285.c
+++ b/drivers/tty/serial/21285.c
@@ -243,7 +243,7 @@ static void serial21285_shutdown(struct uart_port *port)
 
 static void
 serial21285_set_termios(struct uart_port *port, struct ktermios *termios,
-			struct ktermios *old)
+			const struct ktermios *old)
 {
 	unsigned long flags;
 	unsigned int baud, quot, h_lcr, b;
diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
index 8efdc271eb75..fa8ccf204d86 100644
--- a/drivers/tty/serial/8250/8250_bcm7271.c
+++ b/drivers/tty/serial/8250/8250_bcm7271.c
@@ -755,7 +755,7 @@ static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
 
 static void brcmstb_set_termios(struct uart_port *up,
 				struct ktermios *termios,
-				struct ktermios *old)
+				const struct ktermios *old)
 {
 	struct uart_8250_port *p8250 = up_to_u8250p(up);
 	struct brcmuart_priv *priv = up->private_data;
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 2e83e7367441..94fbf0add2ce 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -298,10 +298,9 @@ static void serial8250_backup_timeout(struct timer_list *t)
 		jiffies + uart_poll_timeout(&up->port) + HZ / 5);
 }
 
-static int univ8250_setup_irq(struct uart_8250_port *up)
+static void univ8250_setup_timer(struct uart_8250_port *up)
 {
 	struct uart_port *port = &up->port;
-	int retval = 0;
 
 	/*
 	 * The above check will only give an accurate result the first time
@@ -322,10 +321,16 @@ static int univ8250_setup_irq(struct uart_8250_port *up)
 	 */
 	if (!port->irq)
 		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
-	else
-		retval = serial_link_irq_chain(up);
+}
 
-	return retval;
+static int univ8250_setup_irq(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+
+	if (port->irq)
+		return serial_link_irq_chain(up);
+
+	return 0;
 }
 
 static void univ8250_release_irq(struct uart_8250_port *up)
@@ -381,6 +386,7 @@ static struct uart_ops univ8250_port_ops;
 static const struct uart_8250_ops univ8250_driver_ops = {
 	.setup_irq	= univ8250_setup_irq,
 	.release_irq	= univ8250_release_irq,
+	.setup_timer	= univ8250_setup_timer,
 };
 
 static struct uart_8250_port serial8250_ports[UART_NR];
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index a8dba4a0a8fb..b85c82616e8c 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -26,9 +26,7 @@ static void __dma_tx_complete(void *param)
 
 	dma->tx_running = 0;
 
-	xmit->tail += dma->tx_size;
-	xmit->tail &= UART_XMIT_SIZE - 1;
-	p->port.icount.tx += dma->tx_size;
+	uart_xmit_advance(&p->port, dma->tx_size);
 
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(&p->port);
@@ -107,8 +105,7 @@ int serial8250_tx_dma(struct uart_8250_port *p)
 
 	dma_async_issue_pending(dma->txchan);
 	serial8250_clear_THRI(p);
-	if (dma->tx_err)
-		dma->tx_err = 0;
+	dma->tx_err = 0;
 
 	return 0;
 err:
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index a604b42e4458..7db51781289e 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -350,7 +350,7 @@ dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
 }
 
 static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
-			       struct ktermios *old)
+			       const struct ktermios *old)
 {
 	unsigned long newrate = tty_termios_baud_rate(termios) * 16;
 	struct dw8250_data *d = to_dw8250_data(p->private_data);
diff --git a/drivers/tty/serial/8250/8250_dwlib.c b/drivers/tty/serial/8250/8250_dwlib.c
index dbe4d44f60d4..75f32f054ebb 100644
--- a/drivers/tty/serial/8250/8250_dwlib.c
+++ b/drivers/tty/serial/8250/8250_dwlib.c
@@ -92,7 +92,8 @@ static void dw8250_set_divisor(struct uart_port *p, unsigned int baud,
 	serial8250_do_set_divisor(p, baud, quot, quot_frac);
 }
 
-void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, struct ktermios *old)
+void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios,
+			   const struct ktermios *old)
 {
 	p->status &= ~UPSTAT_AUTOCTS;
 	if (termios->c_cflag & CRTSCTS)
diff --git a/drivers/tty/serial/8250/8250_dwlib.h b/drivers/tty/serial/8250/8250_dwlib.h
index 055bfdc87985..f13e91f2cace 100644
--- a/drivers/tty/serial/8250/8250_dwlib.h
+++ b/drivers/tty/serial/8250/8250_dwlib.h
@@ -47,7 +47,7 @@ struct dw8250_data {
 	unsigned int		uart_16550_compatible:1;
 };
 
-void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, struct ktermios *old);
+void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, const struct ktermios *old);
 void dw8250_setup_port(struct uart_port *p);
 
 static inline struct dw8250_data *to_dw8250_data(struct dw8250_port_data *data)
diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
index 65b6b3cbaff6..e2aa2a1a02dd 100644
--- a/drivers/tty/serial/8250/8250_fintek.c
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -278,7 +278,7 @@ static void fintek_8250_set_max_fifo(struct fintek_8250 *pdata)
 
 static void fintek_8250_set_termios(struct uart_port *port,
 				    struct ktermios *termios,
-				    struct ktermios *old)
+				    const struct ktermios *old)
 {
 	struct fintek_8250 *pdata = port->private_data;
 	unsigned int baud = tty_termios_baud_rate(termios);
diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index 4ba43bef9933..44cc755b1a29 100644
--- a/drivers/tty/serial/8250/8250_lpss.c
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -70,7 +70,7 @@ static inline struct lpss8250 *to_lpss8250(struct dw8250_port_data *data)
 }
 
 static void byt_set_termios(struct uart_port *p, struct ktermios *termios,
-			    struct ktermios *old)
+			    const struct ktermios *old)
 {
 	unsigned int baud = tty_termios_baud_rate(termios);
 	struct lpss8250 *lpss = to_lpss8250(p->private_data);
diff --git a/drivers/tty/serial/8250/8250_men_mcb.c b/drivers/tty/serial/8250/8250_men_mcb.c
index 737c4c31e8a0..f46ca13ff4aa 100644
--- a/drivers/tty/serial/8250/8250_men_mcb.c
+++ b/drivers/tty/serial/8250/8250_men_mcb.c
@@ -7,7 +7,6 @@
 #include <linux/serial.h>
 #include <linux/serial_core.h>
 #include <linux/serial_8250.h>
-#include <uapi/linux/serial_core.h>
 
 #define MEN_UART_ID_Z025 0x19
 #define MEN_UART_ID_Z057 0x39
diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c
index a2a03acb04ad..2cc78a4bf7a1 100644
--- a/drivers/tty/serial/8250/8250_mid.c
+++ b/drivers/tty/serial/8250/8250_mid.c
@@ -206,9 +206,8 @@ static void dnv_exit(struct mid8250 *mid)
 
 /*****************************************************************************/
 
-static void mid8250_set_termios(struct uart_port *p,
-				struct ktermios *termios,
-				struct ktermios *old)
+static void mid8250_set_termios(struct uart_port *p, struct ktermios *termios,
+				const struct ktermios *old)
 {
 	unsigned int baud = tty_termios_baud_rate(termios);
 	struct mid8250 *mid = p->private_data;
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 54051ec7b499..fb1d5ec0940e 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -291,7 +291,7 @@ static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
 
 static void
 mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
-			struct ktermios *old)
+		    const struct ktermios *old)
 {
 	static const unsigned short fraction_L_mapping[] = {
 		0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index f7fbef83583c..41b8c6b27136 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -342,6 +342,9 @@ static void omap8250_restore_regs(struct uart_8250_port *up)
 	omap8250_update_mdr1(up, priv);
 
 	up->port.ops->set_mctrl(&up->port, up->port.mctrl);
+
+	if (up->port.rs485.flags & SER_RS485_ENABLED)
+		serial8250_em485_stop_tx(up);
 }
 
 /*
@@ -350,7 +353,7 @@ static void omap8250_restore_regs(struct uart_8250_port *up)
  */
 static void omap_8250_set_termios(struct uart_port *port,
 				  struct ktermios *termios,
-				  struct ktermios *old)
+				  const struct ktermios *old)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 	struct omap8250_priv *priv = up->port.private_data;
@@ -984,9 +987,7 @@ static void omap_8250_dma_tx_complete(void *param)
 
 	dma->tx_running = 0;
 
-	xmit->tail += dma->tx_size;
-	xmit->tail &= UART_XMIT_SIZE - 1;
-	p->port.icount.tx += dma->tx_size;
+	uart_xmit_advance(&p->port, dma->tx_size);
 
 	if (priv->delayed_restore) {
 		priv->delayed_restore = 0;
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 6f66dc2ebacc..8e9f247590bd 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1232,6 +1232,10 @@ static void pci_oxsemi_tornado_set_mctrl(struct uart_port *port,
 	serial8250_do_set_mctrl(port, mctrl);
 }
 
+/*
+ * We require EFR features for clock programming, so set UPF_FULL_PROBE
+ * for full probing regardless of CONFIG_SERIAL_8250_16550A_VARIANTS setting.
+ */
 static int pci_oxsemi_tornado_setup(struct serial_private *priv,
 				    const struct pciserial_board *board,
 				    struct uart_8250_port *up, int idx)
@@ -1239,6 +1243,7 @@ static int pci_oxsemi_tornado_setup(struct serial_private *priv,
 	struct pci_dev *dev = priv->dev;
 
 	if (pci_oxsemi_tornado_p(dev)) {
+		up->port.flags |= UPF_FULL_PROBE;
 		up->port.get_divisor = pci_oxsemi_tornado_get_divisor;
 		up->port.set_divisor = pci_oxsemi_tornado_set_divisor;
 		up->port.set_mctrl = pci_oxsemi_tornado_set_mctrl;
@@ -1627,7 +1632,6 @@ static int pci_fintek_init(struct pci_dev *dev)
 	resource_size_t bar_data[3];
 	u8 config_base;
 	struct serial_private *priv = pci_get_drvdata(dev);
-	struct uart_8250_port *port;
 
 	if (!(pci_resource_flags(dev, 5) & IORESOURCE_IO) ||
 			!(pci_resource_flags(dev, 4) & IORESOURCE_IO) ||
@@ -1674,13 +1678,7 @@ static int pci_fintek_init(struct pci_dev *dev)
 
 		pci_write_config_byte(dev, config_base + 0x06, dev->irq);
 
-		if (priv) {
-			/* re-apply RS232/485 mode when
-			 * pciserial_resume_ports()
-			 */
-			port = serial8250_get_port(priv->line[i]);
-			uart_rs485_config(&port->port);
-		} else {
+		if (!priv) {
 			/* First init without port data
 			 * force init to RS232 Mode
 			 */
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 39b35a61958c..fe8662cd9402 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -600,7 +600,7 @@ EXPORT_SYMBOL_GPL(serial8250_rpm_put);
 static int serial8250_em485_init(struct uart_8250_port *p)
 {
 	if (p->em485)
-		return 0;
+		goto deassert_rts;
 
 	p->em485 = kmalloc(sizeof(struct uart_8250_em485), GFP_ATOMIC);
 	if (!p->em485)
@@ -616,7 +616,9 @@ static int serial8250_em485_init(struct uart_8250_port *p)
 	p->em485->active_timer = NULL;
 	p->em485->tx_stopped = true;
 
-	p->rs485_stop_tx(p);
+deassert_rts:
+	if (p->em485->tx_stopped)
+		p->rs485_stop_tx(p);
 
 	return 0;
 }
@@ -752,6 +754,14 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
 	serial8250_rpm_put(p);
 }
 
+static void serial8250_clear_IER(struct uart_8250_port *up)
+{
+	if (up->capabilities & UART_CAP_UUE)
+		serial_out(up, UART_IER, UART_IER_UUE);
+	else
+		serial_out(up, UART_IER, 0);
+}
+
 #ifdef CONFIG_SERIAL_8250_RSA
 /*
  * Attempts to turn on the RSA FIFO.  Returns zero on failure.
@@ -1021,7 +1031,8 @@ static void autoconfig_16550a(struct uart_8250_port *up)
 	up->port.type = PORT_16550A;
 	up->capabilities |= UART_CAP_FIFO;
 
-	if (!IS_ENABLED(CONFIG_SERIAL_8250_16550A_VARIANTS))
+	if (!IS_ENABLED(CONFIG_SERIAL_8250_16550A_VARIANTS) &&
+	    !(up->port.flags & UPF_FULL_PROBE))
 		return;
 
 	/*
@@ -1133,7 +1144,7 @@ static void autoconfig_16550a(struct uart_8250_port *up)
 	 * internal UARTs.
 	 * We're going to explicitly set the UUE bit to 0 before
 	 * trying to write and read a 1 just to make sure it's not
-	 * already a 1 and maybe locked there before we even start start.
+	 * already a 1 and maybe locked there before we even start.
 	 */
 	iersave = serial_in(up, UART_IER);
 	serial_out(up, UART_IER, iersave & ~UART_IER_UUE);
@@ -1329,10 +1340,7 @@ static void autoconfig(struct uart_8250_port *up)
 	serial8250_out_MCR(up, save_mcr);
 	serial8250_clear_fifos(up);
 	serial_in(up, UART_RX);
-	if (up->capabilities & UART_CAP_UUE)
-		serial_out(up, UART_IER, UART_IER_UUE);
-	else
-		serial_out(up, UART_IER, 0);
+	serial8250_clear_IER(up);
 
 out_unlock:
 	spin_unlock_irqrestore(&port->lock, flags);
@@ -2042,6 +2050,9 @@ EXPORT_SYMBOL_GPL(serial8250_do_set_mctrl);
 
 static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
+	if (port->rs485.flags & SER_RS485_ENABLED)
+		return;
+
 	if (port->set_mctrl)
 		port->set_mctrl(port, mctrl);
 	else
@@ -2142,10 +2153,7 @@ static void serial8250_put_poll_char(struct uart_port *port,
 	 *	First save the IER then disable the interrupts
 	 */
 	ier = serial_port_in(port, UART_IER);
-	if (up->capabilities & UART_CAP_UUE)
-		serial_port_out(port, UART_IER, UART_IER_UUE);
-	else
-		serial_port_out(port, UART_IER, 0);
+	serial8250_clear_IER(up);
 
 	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
 	/*
@@ -2294,6 +2302,10 @@ int serial8250_do_startup(struct uart_port *port)
 	if (port->irq && (up->port.flags & UPF_SHARE_IRQ))
 		up->port.irqflags |= IRQF_SHARED;
 
+	retval = up->ops->setup_irq(up);
+	if (retval)
+		goto out;
+
 	if (port->irq && !(up->port.flags & UPF_NO_THRE_TEST)) {
 		unsigned char iir1;
 
@@ -2336,9 +2348,7 @@ int serial8250_do_startup(struct uart_port *port)
 		}
 	}
 
-	retval = up->ops->setup_irq(up);
-	if (retval)
-		goto out;
+	up->ops->setup_timer(up);
 
 	/*
 	 * Now, initialize the UART
@@ -2651,7 +2661,7 @@ static void serial8250_set_divisor(struct uart_port *port, unsigned int baud,
 
 static unsigned int serial8250_get_baud_rate(struct uart_port *port,
 					     struct ktermios *termios,
-					     struct ktermios *old)
+					     const struct ktermios *old)
 {
 	unsigned int tolerance = port->uartclk / 100;
 	unsigned int min;
@@ -2737,7 +2747,7 @@ EXPORT_SYMBOL_GPL(serial8250_update_uartclk);
 
 void
 serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
-			  struct ktermios *old)
+		          const struct ktermios *old)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned char cval;
@@ -2875,7 +2885,7 @@ EXPORT_SYMBOL(serial8250_do_set_termios);
 
 static void
 serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
-		       struct ktermios *old)
+		       const struct ktermios *old)
 {
 	if (port->set_termios)
 		port->set_termios(port, termios, old);
@@ -3187,9 +3197,6 @@ static void serial8250_config_port(struct uart_port *port, int flags)
 	if (flags & UART_CONFIG_TYPE)
 		autoconfig(up);
 
-	if (port->rs485.flags & SER_RS485_ENABLED)
-		uart_rs485_config(port);
-
 	/* if access method is AU, it is a 16550 with a quirk */
 	if (port->type == PORT_16550A && port->iotype == UPIO_AU)
 		up->bugs |= UART_BUG_NOMSR;
@@ -3314,8 +3321,13 @@ static void serial8250_console_restore(struct uart_8250_port *up)
 	unsigned int baud, quot, frac = 0;
 
 	termios.c_cflag = port->cons->cflag;
-	if (port->state->port.tty && termios.c_cflag == 0)
+	termios.c_ispeed = port->cons->ispeed;
+	termios.c_ospeed = port->cons->ospeed;
+	if (port->state->port.tty && termios.c_cflag == 0) {
 		termios.c_cflag = port->state->port.tty->termios.c_cflag;
+		termios.c_ispeed = port->state->port.tty->termios.c_ispeed;
+		termios.c_ospeed = port->state->port.tty->termios.c_ospeed;
+	}
 
 	baud = serial8250_get_baud_rate(port, &termios, NULL);
 	quot = serial8250_get_divisor(port, baud, &frac);
@@ -3383,11 +3395,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 	 *	First save the IER then disable the interrupts
 	 */
 	ier = serial_port_in(port, UART_IER);
-
-	if (up->capabilities & UART_CAP_UUE)
-		serial_port_out(port, UART_IER, UART_IER_UUE);
-	else
-		serial_port_out(port, UART_IER, 0);
+	serial8250_clear_IER(up);
 
 	/* check scratch reg to see if port powered off during system sleep */
 	if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index ba4b63fd511e..13cdd9def087 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -127,6 +127,7 @@ config SERIAL_SB1250_DUART_CONSOLE
 
 config SERIAL_ATMEL
 	bool "AT91 on-chip serial port support"
+	depends on COMMON_CLK
 	depends on ARCH_AT91 || COMPILE_TEST
 	select SERIAL_CORE
 	select SERIAL_MCTRL_GPIO if GPIOLIB
@@ -427,7 +428,7 @@ config SERIAL_PXA
 
 config SERIAL_PXA_NON8250
 	bool
-	depends on !SERIAL_8250
+	depends on !SERIAL_8250 || COMPILE_TEST
 
 config SERIAL_PXA_CONSOLE
 	bool "Console on PXA serial port (DEPRECATED)"
@@ -1325,7 +1326,7 @@ config SERIAL_FSL_LPUART
 
 config SERIAL_FSL_LPUART_CONSOLE
 	bool "Console on Freescale lpuart serial port"
-	depends on SERIAL_FSL_LPUART=y
+	depends on SERIAL_FSL_LPUART
 	select SERIAL_CORE_CONSOLE
 	select SERIAL_EARLYCON
 	help
diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
index cb791c5149a3..c2d154d78e54 100644
--- a/drivers/tty/serial/altera_jtaguart.c
+++ b/drivers/tty/serial/altera_jtaguart.c
@@ -9,6 +9,7 @@
  * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
  */
 
+#include <linux/bitfield.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -48,7 +49,6 @@
 #define ALTERA_JTAGUART_CONTROL_WI_MSK		0x00000200
 #define ALTERA_JTAGUART_CONTROL_AC_MSK		0x00000400
 #define ALTERA_JTAGUART_CONTROL_WSPACE_MSK	0xFFFF0000
-#define ALTERA_JTAGUART_CONTROL_WSPACE_OFF	16
 
 /*
  * Local per-uart structure.
@@ -59,10 +59,19 @@ struct altera_jtaguart {
 	unsigned long imr;	/* Local IMR mirror */
 };
 
+static unsigned int altera_jtaguart_tx_space(struct uart_port *port, u32 *ctlp)
+{
+	u32 ctl = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG);
+
+	if (ctlp)
+		*ctlp = ctl;
+
+	return FIELD_GET(ALTERA_JTAGUART_CONTROL_WSPACE_MSK, ctl);
+}
+
 static unsigned int altera_jtaguart_tx_empty(struct uart_port *port)
 {
-	return (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
-		ALTERA_JTAGUART_CONTROL_WSPACE_MSK) ? TIOCSER_TEMT : 0;
+	return altera_jtaguart_tx_space(port, NULL) ? TIOCSER_TEMT : 0;
 }
 
 static unsigned int altera_jtaguart_get_mctrl(struct uart_port *port)
@@ -106,8 +115,8 @@ static void altera_jtaguart_break_ctl(struct uart_port *port, int break_state)
 }
 
 static void altera_jtaguart_set_termios(struct uart_port *port,
-					struct ktermios *termios,
-					struct ktermios *old)
+				        struct ktermios *termios,
+				        const struct ktermios *old)
 {
 	/* Just copy the old termios settings back */
 	if (old)
@@ -150,9 +159,7 @@ static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp)
 
 	pending = uart_circ_chars_pending(xmit);
 	if (pending > 0) {
-		count = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
-				ALTERA_JTAGUART_CONTROL_WSPACE_MSK) >>
-			ALTERA_JTAGUART_CONTROL_WSPACE_OFF;
+		count = altera_jtaguart_tx_space(port, NULL);
 		if (count > pending)
 			count = pending;
 		if (count > 0) {
@@ -298,17 +305,17 @@ static struct altera_jtaguart altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];
 #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
 static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c)
 {
-	unsigned long status;
 	unsigned long flags;
+	u32 status;
 
 	spin_lock_irqsave(&port->lock, flags);
-	while (((status = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG)) &
-		ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
+	while (!altera_jtaguart_tx_space(port, &status)) {
+		spin_unlock_irqrestore(&port->lock, flags);
+
 		if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
-			spin_unlock_irqrestore(&port->lock, flags);
 			return;	/* no connection activity */
 		}
-		spin_unlock_irqrestore(&port->lock, flags);
+
 		cpu_relax();
 		spin_lock_irqsave(&port->lock, flags);
 	}
@@ -321,8 +328,7 @@ static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c
 	unsigned long flags;
 
 	spin_lock_irqsave(&port->lock, flags);
-	while ((readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
-		ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
+	while (!altera_jtaguart_tx_space(port, NULL)) {
 		spin_unlock_irqrestore(&port->lock, flags);
 		cpu_relax();
 		spin_lock_irqsave(&port->lock, flags);
diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index 8b749ed557c6..82f2790de28d 100644
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -175,7 +175,7 @@ static void altera_uart_break_ctl(struct uart_port *port, int break_state)
 
 static void altera_uart_set_termios(struct uart_port *port,
 				    struct ktermios *termios,
-				    struct ktermios *old)
+				    const struct ktermios *old)
 {
 	unsigned long flags;
 	unsigned int baud, baudclk;
@@ -199,9 +199,8 @@ static void altera_uart_set_termios(struct uart_port *port,
 	 */
 }
 
-static void altera_uart_rx_chars(struct altera_uart *pp)
+static void altera_uart_rx_chars(struct uart_port *port)
 {
-	struct uart_port *port = &pp->port;
 	unsigned char ch, flag;
 	unsigned short status;
 
@@ -246,9 +245,8 @@ static void altera_uart_rx_chars(struct altera_uart *pp)
 	tty_flip_buffer_push(&port->state->port);
 }
 
-static void altera_uart_tx_chars(struct altera_uart *pp)
+static void altera_uart_tx_chars(struct uart_port *port)
 {
-	struct uart_port *port = &pp->port;
 	struct circ_buf *xmit = &port->state->xmit;
 
 	if (port->x_char) {
@@ -272,10 +270,8 @@ static void altera_uart_tx_chars(struct altera_uart *pp)
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(port);
 
-	if (xmit->head == xmit->tail) {
-		pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
-		altera_uart_update_ctrl_reg(pp);
-	}
+	if (uart_circ_empty(xmit))
+		altera_uart_stop_tx(port);
 }
 
 static irqreturn_t altera_uart_interrupt(int irq, void *data)
@@ -288,9 +284,9 @@ static irqreturn_t altera_uart_interrupt(int irq, void *data)
 
 	spin_lock(&port->lock);
 	if (isr & ALTERA_UART_STATUS_RRDY_MSK)
-		altera_uart_rx_chars(pp);
+		altera_uart_rx_chars(port);
 	if (isr & ALTERA_UART_STATUS_TRDY_MSK)
-		altera_uart_tx_chars(pp);
+		altera_uart_tx_chars(port);
 	spin_unlock(&port->lock);
 
 	return IRQ_RETVAL(isr);
diff --git a/drivers/tty/serial/amba-pl010.c b/drivers/tty/serial/amba-pl010.c
index fae0b581ff42..af27fb8ec145 100644
--- a/drivers/tty/serial/amba-pl010.c
+++ b/drivers/tty/serial/amba-pl010.c
@@ -370,7 +370,7 @@ static void pl010_shutdown(struct uart_port *port)
 
 static void
 pl010_set_termios(struct uart_port *port, struct ktermios *termios,
-		     struct ktermios *old)
+		  const struct ktermios *old)
 {
 	unsigned int lcr_h, old_cr;
 	unsigned long flags;
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 15f0e4d88c5a..5cdced39eafd 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2030,7 +2030,7 @@ pl011_setup_status_masks(struct uart_port *port, struct ktermios *termios)
 
 static void
 pl011_set_termios(struct uart_port *port, struct ktermios *termios,
-		     struct ktermios *old)
+		  const struct ktermios *old)
 {
 	struct uart_amba_port *uap =
 	    container_of(port, struct uart_amba_port, port);
@@ -2162,7 +2162,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
 
 static void
 sbsa_uart_set_termios(struct uart_port *port, struct ktermios *termios,
-		      struct ktermios *old)
+		      const struct ktermios *old)
 {
 	struct uart_amba_port *uap =
 	    container_of(port, struct uart_amba_port, port);
@@ -2777,6 +2777,7 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 	struct uart_amba_port *uap;
 	struct vendor_data *vendor = id->data;
 	int portnr, ret;
+	u32 val;
 
 	portnr = pl011_find_free_port();
 	if (portnr < 0)
@@ -2801,6 +2802,21 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 	uap->port.rs485_supported = pl011_rs485_supported;
 	snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
 
+	if (device_property_read_u32(&dev->dev, "reg-io-width", &val) == 0) {
+		switch (val) {
+		case 1:
+			uap->port.iotype = UPIO_MEM;
+			break;
+		case 4:
+			uap->port.iotype = UPIO_MEM32;
+			break;
+		default:
+			dev_warn(&dev->dev, "unsupported reg-io-width (%d)\n",
+				 val);
+			return -EINVAL;
+		}
+	}
+
 	ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr);
 	if (ret)
 		return ret;
diff --git a/drivers/tty/serial/apbuart.c b/drivers/tty/serial/apbuart.c
index 9ef82d870ff2..450f4edfda0f 100644
--- a/drivers/tty/serial/apbuart.c
+++ b/drivers/tty/serial/apbuart.c
@@ -228,7 +228,7 @@ static void apbuart_shutdown(struct uart_port *port)
 }
 
 static void apbuart_set_termios(struct uart_port *port,
-				struct ktermios *termios, struct ktermios *old)
+				struct ktermios *termios, const struct ktermios *old)
 {
 	unsigned int cr;
 	unsigned long flags;
diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c
index 32caeac12985..925484a42c82 100644
--- a/drivers/tty/serial/ar933x_uart.c
+++ b/drivers/tty/serial/ar933x_uart.c
@@ -283,7 +283,7 @@ static void ar933x_uart_get_scale_step(unsigned int clk,
 
 static void ar933x_uart_set_termios(struct uart_port *port,
 				    struct ktermios *new,
-				    struct ktermios *old)
+				    const struct ktermios *old)
 {
 	struct ar933x_uart_port *up =
 		container_of(port, struct ar933x_uart_port, port);
@@ -583,6 +583,13 @@ static const struct uart_ops ar933x_uart_ops = {
 static int ar933x_config_rs485(struct uart_port *port, struct ktermios *termios,
 				struct serial_rs485 *rs485conf)
 {
+	struct ar933x_uart_port *up =
+			container_of(port, struct ar933x_uart_port, port);
+
+	if (port->rs485.flags & SER_RS485_ENABLED)
+		gpiod_set_value(up->rts_gpiod,
+			!!(rs485conf->flags & SER_RS485_RTS_AFTER_SEND));
+
 	return 0;
 }
 
diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
index 2a09e92ef9ed..2a65ea2660e1 100644
--- a/drivers/tty/serial/arc_uart.c
+++ b/drivers/tty/serial/arc_uart.c
@@ -351,7 +351,7 @@ static void arc_serial_shutdown(struct uart_port *port)
 
 static void
 arc_serial_set_termios(struct uart_port *port, struct ktermios *new,
-		       struct ktermios *old)
+		       const struct ktermios *old)
 {
 	struct arc_uart_port *uart = to_arc_port(port);
 	unsigned int baud, uartl, uarth, hw_val;
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 7450d3853031..bd07f79a2df9 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -15,6 +15,7 @@
 #include <linux/init.h>
 #include <linux/serial.h>
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/console.h>
 #include <linux/sysrq.h>
 #include <linux/tty_flip.h>
@@ -110,6 +111,7 @@ struct atmel_uart_char {
 struct atmel_uart_port {
 	struct uart_port	uart;		/* uart */
 	struct clk		*clk;		/* uart clock */
+	struct clk		*gclk;		/* uart generic clock */
 	int			may_wakeup;	/* cached value of device_may_wakeup for times we need to disable it */
 	u32			backup_imr;	/* IMR saved during suspend */
 	int			break_active;	/* break being received */
@@ -150,6 +152,7 @@ struct atmel_uart_port {
 	u32			rts_low;
 	bool			ms_irq_enabled;
 	u32			rtor;	/* address of receiver timeout register if it exists */
+	bool			is_usart;
 	bool			has_frac_baudrate;
 	bool			has_hw_timer;
 	struct timer_list	uart_timer;
@@ -228,6 +231,11 @@ static inline int atmel_uart_is_half_duplex(struct uart_port *port)
 		(port->iso7816.flags & SER_ISO7816_ENABLED);
 }
 
+static inline int atmel_error_rate(int desired_value, int actual_value)
+{
+	return 100 - (desired_value * 100) / actual_value;
+}
+
 #ifdef CONFIG_SERIAL_ATMEL_PDC
 static bool atmel_use_pdc_rx(struct uart_port *port)
 {
@@ -1825,6 +1833,7 @@ static void atmel_get_ip_name(struct uart_port *port)
 	 */
 	atmel_port->has_frac_baudrate = false;
 	atmel_port->has_hw_timer = false;
+	atmel_port->is_usart = false;
 
 	if (name == new_uart) {
 		dev_dbg(port->dev, "Uart with hw timer");
@@ -1834,6 +1843,7 @@ static void atmel_get_ip_name(struct uart_port *port)
 		dev_dbg(port->dev, "Usart\n");
 		atmel_port->has_frac_baudrate = true;
 		atmel_port->has_hw_timer = true;
+		atmel_port->is_usart = true;
 		atmel_port->rtor = ATMEL_US_RTOR;
 		version = atmel_uart_readl(port, ATMEL_US_VERSION);
 		switch (version) {
@@ -1863,6 +1873,7 @@ static void atmel_get_ip_name(struct uart_port *port)
 			dev_dbg(port->dev, "This version is usart\n");
 			atmel_port->has_frac_baudrate = true;
 			atmel_port->has_hw_timer = true;
+			atmel_port->is_usart = true;
 			atmel_port->rtor = ATMEL_US_RTOR;
 			break;
 		case 0x203:
@@ -2113,6 +2124,8 @@ static void atmel_serial_pm(struct uart_port *port, unsigned int state,
 		 * This is called on uart_close() or a suspend event.
 		 */
 		clk_disable_unprepare(atmel_port->clk);
+		if (__clk_is_enabled(atmel_port->gclk))
+			clk_disable_unprepare(atmel_port->gclk);
 		break;
 	default:
 		dev_err(port->dev, "atmel_serial: unknown pm %d\n", state);
@@ -2122,19 +2135,25 @@ static void atmel_serial_pm(struct uart_port *port, unsigned int state,
 /*
  * Change the port parameters
  */
-static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
-			      struct ktermios *old)
+static void atmel_set_termios(struct uart_port *port,
+			      struct ktermios *termios,
+			      const struct ktermios *old)
 {
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 	unsigned long flags;
-	unsigned int old_mode, mode, imr, quot, baud, div, cd, fp = 0;
+	unsigned int old_mode, mode, imr, quot, div, cd, fp = 0;
+	unsigned int baud, actual_baud, gclk_rate;
+	int ret;
 
 	/* save the current mode register */
 	mode = old_mode = atmel_uart_readl(port, ATMEL_US_MR);
 
 	/* reset the mode, clock divisor, parity, stop bits and data size */
-	mode &= ~(ATMEL_US_USCLKS | ATMEL_US_CHRL | ATMEL_US_NBSTOP |
-		  ATMEL_US_PAR | ATMEL_US_USMODE);
+	if (atmel_port->is_usart)
+		mode &= ~(ATMEL_US_NBSTOP | ATMEL_US_PAR | ATMEL_US_CHRL |
+			  ATMEL_US_USCLKS | ATMEL_US_USMODE);
+	else
+		mode &= ~(ATMEL_UA_BRSRCCK | ATMEL_US_PAR | ATMEL_UA_FILTER);
 
 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
 
@@ -2282,10 +2301,60 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
 		cd = uart_get_divisor(port, baud);
 	}
 
-	if (cd > 65535) {	/* BRGR is 16-bit, so switch to slower clock */
+	/*
+	 * If the current value of the Clock Divisor surpasses the 16 bit
+	 * ATMEL_US_CD mask and the IP is USART, switch to the Peripheral
+	 * Clock implicitly divided by 8.
+	 * If the IP is UART however, keep the highest possible value for
+	 * the CD and avoid needless division of CD, since UART IP's do not
+	 * support implicit division of the Peripheral Clock.
+	 */
+	if (atmel_port->is_usart && cd > ATMEL_US_CD) {
 		cd /= 8;
 		mode |= ATMEL_US_USCLKS_MCK_DIV8;
+	} else {
+		cd = min_t(unsigned int, cd, ATMEL_US_CD);
+	}
+
+	/*
+	 * If there is no Fractional Part, there is a high chance that
+	 * we may be able to generate a baudrate closer to the desired one
+	 * if we use the GCLK as the clock source driving the baudrate
+	 * generator.
+	 */
+	if (!atmel_port->has_frac_baudrate) {
+		if (__clk_is_enabled(atmel_port->gclk))
+			clk_disable_unprepare(atmel_port->gclk);
+		gclk_rate = clk_round_rate(atmel_port->gclk, 16 * baud);
+		actual_baud = clk_get_rate(atmel_port->clk) / (16 * cd);
+		if (gclk_rate && abs(atmel_error_rate(baud, actual_baud)) >
+		    abs(atmel_error_rate(baud, gclk_rate / 16))) {
+			clk_set_rate(atmel_port->gclk, 16 * baud);
+			ret = clk_prepare_enable(atmel_port->gclk);
+			if (ret)
+				goto gclk_fail;
+
+			if (atmel_port->is_usart) {
+				mode &= ~ATMEL_US_USCLKS;
+				mode |= ATMEL_US_USCLKS_GCLK;
+			} else {
+				mode |= ATMEL_UA_BRSRCCK;
+			}
+
+			/*
+			 * Set the Clock Divisor for GCLK to 1.
+			 * Since we were able to generate the smallest
+			 * multiple of the desired baudrate times 16,
+			 * then we surely can generate a bigger multiple
+			 * with the exact error rate for an equally increased
+			 * CD. Thus no need to take into account
+			 * a higher value for CD.
+			 */
+			cd = 1;
+		}
 	}
+
+gclk_fail:
 	quot = cd | fp << ATMEL_US_FP_OFFSET;
 
 	if (!(port->iso7816.flags & SER_ISO7816_ENABLED))
@@ -2881,6 +2950,12 @@ static int atmel_serial_probe(struct platform_device *pdev)
 	if (ret)
 		goto err;
 
+	atmel_port->gclk = devm_clk_get_optional(&pdev->dev, "gclk");
+	if (IS_ERR(atmel_port->gclk)) {
+		ret = PTR_ERR(atmel_port->gclk);
+		goto err_clk_disable_unprepare;
+	}
+
 	ret = atmel_init_port(atmel_port, pdev);
 	if (ret)
 		goto err_clk_disable_unprepare;
diff --git a/drivers/tty/serial/atmel_serial.h b/drivers/tty/serial/atmel_serial.h
index 0d8a0f9cc5c3..87f8f7996307 100644
--- a/drivers/tty/serial/atmel_serial.h
+++ b/drivers/tty/serial/atmel_serial.h
@@ -9,6 +9,8 @@
  * Based on AT91RM9200 datasheet revision E.
  */
 
+#include <linux/bitfield.h>
+
 #ifndef ATMEL_SERIAL_H
 #define ATMEL_SERIAL_H
 
@@ -39,39 +41,42 @@
 
 #define ATMEL_US_MR		0x04	/* Mode Register */
 #define	ATMEL_US_USMODE		GENMASK(3, 0)	/* Mode of the USART */
-#define		ATMEL_US_USMODE_NORMAL		0
-#define		ATMEL_US_USMODE_RS485		1
-#define		ATMEL_US_USMODE_HWHS		2
-#define		ATMEL_US_USMODE_MODEM		3
-#define		ATMEL_US_USMODE_ISO7816_T0	4
-#define		ATMEL_US_USMODE_ISO7816_T1	6
-#define		ATMEL_US_USMODE_IRDA		8
+#define		ATMEL_US_USMODE_NORMAL		FIELD_PREP(ATMEL_US_USMODE, 0)
+#define		ATMEL_US_USMODE_RS485		FIELD_PREP(ATMEL_US_USMODE, 1)
+#define		ATMEL_US_USMODE_HWHS		FIELD_PREP(ATMEL_US_USMODE, 2)
+#define		ATMEL_US_USMODE_MODEM		FIELD_PREP(ATMEL_US_USMODE, 3)
+#define		ATMEL_US_USMODE_ISO7816_T0	FIELD_PREP(ATMEL_US_USMODE, 4)
+#define		ATMEL_US_USMODE_ISO7816_T1	FIELD_PREP(ATMEL_US_USMODE, 6)
+#define		ATMEL_US_USMODE_IRDA		FIELD_PREP(ATMEL_US_USMODE, 8)
 #define	ATMEL_US_USCLKS		GENMASK(5, 4)	/* Clock Selection */
-#define		ATMEL_US_USCLKS_MCK		(0 <<  4)
-#define		ATMEL_US_USCLKS_MCK_DIV8	(1 <<  4)
-#define		ATMEL_US_USCLKS_SCK		(3 <<  4)
+#define		ATMEL_US_USCLKS_MCK		FIELD_PREP(ATMEL_US_USCLKS, 0)
+#define		ATMEL_US_USCLKS_MCK_DIV8	FIELD_PREP(ATMEL_US_USCLKS, 1)
+#define		ATMEL_US_USCLKS_GCLK		FIELD_PREP(ATMEL_US_USCLKS, 2)
+#define		ATMEL_US_USCLKS_SCK		FIELD_PREP(ATMEL_US_USCLKS, 3)
+#define	ATMEL_UA_FILTER		BIT(4)
 #define	ATMEL_US_CHRL		GENMASK(7, 6)	/* Character Length */
-#define		ATMEL_US_CHRL_5			(0 <<  6)
-#define		ATMEL_US_CHRL_6			(1 <<  6)
-#define		ATMEL_US_CHRL_7			(2 <<  6)
-#define		ATMEL_US_CHRL_8			(3 <<  6)
+#define		ATMEL_US_CHRL_5			FIELD_PREP(ATMEL_US_CHRL, 0)
+#define		ATMEL_US_CHRL_6			FIELD_PREP(ATMEL_US_CHRL, 1)
+#define		ATMEL_US_CHRL_7			FIELD_PREP(ATMEL_US_CHRL, 2)
+#define		ATMEL_US_CHRL_8			FIELD_PREP(ATMEL_US_CHRL, 3)
 #define	ATMEL_US_SYNC		BIT(8)		/* Synchronous Mode Select */
 #define	ATMEL_US_PAR		GENMASK(11, 9)	/* Parity Type */
-#define		ATMEL_US_PAR_EVEN		(0 <<  9)
-#define		ATMEL_US_PAR_ODD		(1 <<  9)
-#define		ATMEL_US_PAR_SPACE		(2 <<  9)
-#define		ATMEL_US_PAR_MARK		(3 <<  9)
-#define		ATMEL_US_PAR_NONE		(4 <<  9)
-#define		ATMEL_US_PAR_MULTI_DROP		(6 <<  9)
+#define		ATMEL_US_PAR_EVEN		FIELD_PREP(ATMEL_US_PAR, 0)
+#define		ATMEL_US_PAR_ODD		FIELD_PREP(ATMEL_US_PAR, 1)
+#define		ATMEL_US_PAR_SPACE		FIELD_PREP(ATMEL_US_PAR, 2)
+#define		ATMEL_US_PAR_MARK		FIELD_PREP(ATMEL_US_PAR, 3)
+#define		ATMEL_US_PAR_NONE		FIELD_PREP(ATMEL_US_PAR, 4)
+#define		ATMEL_US_PAR_MULTI_DROP		FIELD_PREP(ATMEL_US_PAR, 6)
 #define	ATMEL_US_NBSTOP		GENMASK(13, 12)	/* Number of Stop Bits */
-#define		ATMEL_US_NBSTOP_1		(0 << 12)
-#define		ATMEL_US_NBSTOP_1_5		(1 << 12)
-#define		ATMEL_US_NBSTOP_2		(2 << 12)
+#define		ATMEL_US_NBSTOP_1		FIELD_PREP(ATMEL_US_NBSTOP, 0)
+#define		ATMEL_US_NBSTOP_1_5		FIELD_PREP(ATMEL_US_NBSTOP, 1)
+#define		ATMEL_US_NBSTOP_2		FIELD_PREP(ATMEL_US_NBSTOP, 2)
+#define	ATMEL_UA_BRSRCCK	BIT(12)	/* Clock Selection for UART */
 #define	ATMEL_US_CHMODE		GENMASK(15, 14)	/* Channel Mode */
-#define		ATMEL_US_CHMODE_NORMAL		(0 << 14)
-#define		ATMEL_US_CHMODE_ECHO		(1 << 14)
-#define		ATMEL_US_CHMODE_LOC_LOOP	(2 << 14)
-#define		ATMEL_US_CHMODE_REM_LOOP	(3 << 14)
+#define		ATMEL_US_CHMODE_NORMAL		FIELD_PREP(ATMEL_US_CHMODE, 0)
+#define		ATMEL_US_CHMODE_ECHO		FIELD_PREP(ATMEL_US_CHMODE, 1)
+#define		ATMEL_US_CHMODE_LOC_LOOP	FIELD_PREP(ATMEL_US_CHMODE, 2)
+#define		ATMEL_US_CHMODE_REM_LOOP	FIELD_PREP(ATMEL_US_CHMODE, 3)
 #define	ATMEL_US_MSBF		BIT(16)	/* Bit Order */
 #define	ATMEL_US_MODE9		BIT(17)	/* 9-bit Character Length */
 #define	ATMEL_US_CLKO		BIT(18)	/* Clock Output Select */
@@ -79,7 +84,7 @@
 #define	ATMEL_US_INACK		BIT(20)	/* Inhibit Non Acknowledge */
 #define	ATMEL_US_DSNACK		BIT(21)	/* Disable Successive NACK */
 #define	ATMEL_US_MAX_ITER_MASK	GENMASK(26, 24)	/* Max Iterations */
-#define	ATMEL_US_MAX_ITER(n)	(((n) << 24) & ATMEL_US_MAX_ITER_MASK)
+#define	ATMEL_US_MAX_ITER(n)	FIELD_PREP(ATMEL_US_MAX_ITER_MASK, (n))
 #define	ATMEL_US_FILTER		BIT(28)	/* Infrared Receive Line Filter */
 
 #define ATMEL_US_IER		0x08	/* Interrupt Enable Register */
@@ -131,19 +136,19 @@
 
 #define ATMEL_US_CMPR		0x90	/* Comparaison Register */
 #define ATMEL_US_FMR		0xa0	/* FIFO Mode Register */
-#define	ATMEL_US_TXRDYM(data)	(((data) & 0x3) << 0)	/* TX Ready Mode */
-#define	ATMEL_US_RXRDYM(data)	(((data) & 0x3) << 4)	/* RX Ready Mode */
+#define	ATMEL_US_TXRDYM(data)	FIELD_PREP(GENMASK(1, 0), (data))	/* TX Ready Mode */
+#define	ATMEL_US_RXRDYM(data)	FIELD_PREP(GENMASK(5, 4), (data))	/* RX Ready Mode */
 #define		ATMEL_US_ONE_DATA	0x0
 #define		ATMEL_US_TWO_DATA	0x1
 #define		ATMEL_US_FOUR_DATA	0x2
 #define	ATMEL_US_FRTSC		BIT(7)	/* FIFO RTS pin Control */
-#define	ATMEL_US_TXFTHRES(thr)	(((thr) & 0x3f) << 8)	/* TX FIFO Threshold */
-#define	ATMEL_US_RXFTHRES(thr)	(((thr) & 0x3f) << 16)	/* RX FIFO Threshold */
-#define	ATMEL_US_RXFTHRES2(thr)	(((thr) & 0x3f) << 24)	/* RX FIFO Threshold2 */
+#define	ATMEL_US_TXFTHRES(thr)	FIELD_PREP(GENMASK(13, 8), (thr))	/* TX FIFO Threshold */
+#define	ATMEL_US_RXFTHRES(thr)	FIELD_PREP(GENMASK(21, 16), (thr))	/* RX FIFO Threshold */
+#define	ATMEL_US_RXFTHRES2(thr)	FIELD_PREP(GENMASK(29, 24), (thr))	/* RX FIFO Threshold2 */
 
 #define ATMEL_US_FLR		0xa4	/* FIFO Level Register */
-#define	ATMEL_US_TXFL(reg)	(((reg) >> 0) & 0x3f)	/* TX FIFO Level */
-#define	ATMEL_US_RXFL(reg)	(((reg) >> 16) & 0x3f)	/* RX FIFO Level */
+#define	ATMEL_US_TXFL(reg)	FIELD_GET(GENMASK(5, 0), (reg))		/* TX FIFO Level */
+#define	ATMEL_US_RXFL(reg)	FIELD_GET(GENMASK(21, 16), (reg))	/* RX FIFO Level */
 
 #define ATMEL_US_FIER		0xa8	/* FIFO Interrupt Enable Register */
 #define ATMEL_US_FIDR		0xac	/* FIFO Interrupt Disable Register */
diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c
index 53b43174aa40..5d9737c2d1f2 100644
--- a/drivers/tty/serial/bcm63xx_uart.c
+++ b/drivers/tty/serial/bcm63xx_uart.c
@@ -492,9 +492,8 @@ static void bcm_uart_shutdown(struct uart_port *port)
 /*
  * serial core request to change current uart setting
  */
-static void bcm_uart_set_termios(struct uart_port *port,
-				 struct ktermios *new,
-				 struct ktermios *old)
+static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
+				 const struct ktermios *old)
 {
 	unsigned int ctl, baud, quot, ier;
 	unsigned long flags;
diff --git a/drivers/tty/serial/clps711x.c b/drivers/tty/serial/clps711x.c
index b9b66ad31a08..404b43a5ae33 100644
--- a/drivers/tty/serial/clps711x.c
+++ b/drivers/tty/serial/clps711x.c
@@ -251,7 +251,7 @@ static void uart_clps711x_shutdown(struct uart_port *port)
 
 static void uart_clps711x_set_termios(struct uart_port *port,
 				      struct ktermios *termios,
-				      struct ktermios *old)
+				      const struct ktermios *old)
 {
 	u32 ubrlcr;
 	unsigned int baud, quot;
diff --git a/drivers/tty/serial/cpm_uart/cpm_uart.h b/drivers/tty/serial/cpm_uart/cpm_uart.h
index 8c582779cf22..0577618e78c0 100644
--- a/drivers/tty/serial/cpm_uart/cpm_uart.h
+++ b/drivers/tty/serial/cpm_uart/cpm_uart.h
@@ -87,7 +87,6 @@ struct uart_cpm_port {
 	struct gpio_desc	*gpios[NUM_GPIOS];
 };
 
-extern int cpm_uart_nr;
 extern struct uart_cpm_port cpm_uart_ports[UART_NR];
 
 /* these are located in their respective files */
diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
index db07d6a5d764..b4369ed45ae2 100644
--- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
@@ -484,12 +484,11 @@ static void cpm_uart_shutdown(struct uart_port *port)
 
 static void cpm_uart_set_termios(struct uart_port *port,
                                  struct ktermios *termios,
-                                 struct ktermios *old)
+                                 const struct ktermios *old)
 {
 	int baud;
 	unsigned long flags;
 	u16 cval, scval, prev_mode;
-	int bits, sbits;
 	struct uart_cpm_port *pinfo =
 		container_of(port, struct uart_cpm_port, port);
 	smc_t __iomem *smcp = pinfo->smcp;
@@ -515,28 +514,17 @@ static void cpm_uart_set_termios(struct uart_port *port,
 	if (maxidl > 0x10)
 		maxidl = 0x10;
 
-	/* Character length programmed into the mode register is the
-	 * sum of: 1 start bit, number of data bits, 0 or 1 parity bit,
-	 * 1 or 2 stop bits, minus 1.
-	 * The value 'bits' counts this for us.
-	 */
 	cval = 0;
 	scval = 0;
 
-	/* byte size */
-	bits = tty_get_char_size(termios->c_cflag);
-	sbits = bits - 5;
-
 	if (termios->c_cflag & CSTOPB) {
 		cval |= SMCMR_SL;	/* Two stops */
 		scval |= SCU_PSMR_SL;
-		bits++;
 	}
 
 	if (termios->c_cflag & PARENB) {
 		cval |= SMCMR_PEN;
 		scval |= SCU_PSMR_PEN;
-		bits++;
 		if (!(termios->c_cflag & PARODD)) {
 			cval |= SMCMR_PM_EVEN;
 			scval |= (SCU_PSMR_REVP | SCU_PSMR_TEVP);
@@ -580,12 +568,9 @@ static void cpm_uart_set_termios(struct uart_port *port,
 
 	spin_lock_irqsave(&port->lock, flags);
 
-	/* Start bit has not been added (so don't, because we would just
-	 * subtract it later), and we need to add one for the number of
-	 * stops bits (there is always at least one).
-	 */
-	bits++;
 	if (IS_SMC(pinfo)) {
+		unsigned int bits = tty_get_frame_size(termios->c_cflag);
+
 		/*
 		 * MRBLR can be changed while an SMC/SCC is operating only
 		 * if it is done in a single bus cycle with one 16-bit move
@@ -604,13 +589,17 @@ static void cpm_uart_set_termios(struct uart_port *port,
 		 */
 		prev_mode = in_be16(&smcp->smc_smcmr) & (SMCMR_REN | SMCMR_TEN);
 		/* Output in *one* operation, so we don't interrupt RX/TX if they
-		 * were already enabled. */
-		out_be16(&smcp->smc_smcmr, smcr_mk_clen(bits) | cval |
-		    SMCMR_SM_UART | prev_mode);
+		 * were already enabled.
+		 * Character length programmed into the register is frame bits minus 1.
+		 */
+		out_be16(&smcp->smc_smcmr, smcr_mk_clen(bits - 1) | cval |
+					   SMCMR_SM_UART | prev_mode);
 	} else {
+		unsigned int bits = tty_get_char_size(termios->c_cflag);
+
 		out_be16(&pinfo->sccup->scc_genscc.scc_mrblr, pinfo->rx_fifosize);
 		out_be16(&pinfo->sccup->scc_maxidl, maxidl);
-		out_be16(&sccp->scc_psmr, (sbits << 12) | scval);
+		out_be16(&sccp->scc_psmr, (UART_LCR_WLEN(bits) << 12) | scval);
 	}
 
 	if (pinfo->clk)
@@ -1214,12 +1203,6 @@ static int cpm_uart_init_port(struct device_node *np,
 	pinfo->port.fifosize = pinfo->tx_nrfifos * pinfo->tx_fifosize;
 	spin_lock_init(&pinfo->port.lock);
 
-	pinfo->port.irq = irq_of_parse_and_map(np, 0);
-	if (pinfo->port.irq == NO_IRQ) {
-		ret = -EINVAL;
-		goto out_pram;
-	}
-
 	for (i = 0; i < NUM_GPIOS; i++) {
 		struct gpio_desc *gpiod;
 
@@ -1229,7 +1212,7 @@ static int cpm_uart_init_port(struct device_node *np,
 
 		if (IS_ERR(gpiod)) {
 			ret = PTR_ERR(gpiod);
-			goto out_irq;
+			goto out_pram;
 		}
 
 		if (gpiod) {
@@ -1255,8 +1238,6 @@ static int cpm_uart_init_port(struct device_node *np,
 
 	return cpm_uart_request_port(&pinfo->port);
 
-out_irq:
-	irq_dispose_mapping(pinfo->port.irq);
 out_pram:
 	cpm_uart_unmap_pram(pinfo, pram);
 out_mem:
@@ -1436,11 +1417,17 @@ static int cpm_uart_probe(struct platform_device *ofdev)
 	/* initialize the device pointer for the port */
 	pinfo->port.dev = &ofdev->dev;
 
+	pinfo->port.irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
+	if (!pinfo->port.irq)
+		return -EINVAL;
+
 	ret = cpm_uart_init_port(ofdev->dev.of_node, pinfo);
-	if (ret)
-		return ret;
+	if (!ret)
+		return uart_add_one_port(&cpm_reg, &pinfo->port);
+
+	irq_dispose_mapping(pinfo->port.irq);
 
-	return uart_add_one_port(&cpm_reg, &pinfo->port);
+	return ret;
 }
 
 static int cpm_uart_remove(struct platform_device *ofdev)
diff --git a/drivers/tty/serial/digicolor-usart.c b/drivers/tty/serial/digicolor-usart.c
index af951e6a2ef4..0c0a62346f23 100644
--- a/drivers/tty/serial/digicolor-usart.c
+++ b/drivers/tty/serial/digicolor-usart.c
@@ -287,7 +287,7 @@ static void digicolor_uart_shutdown(struct uart_port *port)
 
 static void digicolor_uart_set_termios(struct uart_port *port,
 				       struct ktermios *termios,
-				       struct ktermios *old)
+				       const struct ktermios *old)
 {
 	unsigned int baud, divisor;
 	u8 config = 0;
diff --git a/drivers/tty/serial/dz.c b/drivers/tty/serial/dz.c
index 2e21acf39720..829b452daee9 100644
--- a/drivers/tty/serial/dz.c
+++ b/drivers/tty/serial/dz.c
@@ -559,7 +559,7 @@ static void dz_reset(struct dz_port *dport)
 }
 
 static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
-			   struct ktermios *old_termios)
+			   const struct ktermios *old_termios)
 {
 	struct dz_port *dport = to_dport(uport);
 	unsigned long flags;
@@ -592,9 +592,12 @@ static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
 
 	baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
 	bflag = dz_encode_baud_rate(baud);
-	if (bflag < 0)	{			/* Try to keep unchanged.  */
-		baud = uart_get_baud_rate(uport, old_termios, NULL, 50, 9600);
-		bflag = dz_encode_baud_rate(baud);
+	if (bflag < 0)	{
+		if (old_termios) {
+			/* Keep unchanged. */
+			baud = tty_termios_baud_rate(old_termios);
+			bflag = dz_encode_baud_rate(baud);
+		}
 		if (bflag < 0)	{		/* Resort to 9600.  */
 			baud = 9600;
 			bflag = DZ_B9600;
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 88d08ba1ca83..a5f380584cda 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -67,7 +67,7 @@ static void __init earlycon_init(struct earlycon_device *device,
 	if (*s)
 		earlycon->index = simple_strtoul(s, NULL, 10);
 	len = s - name;
-	strlcpy(earlycon->name, name, min(len + 1, sizeof(earlycon->name)));
+	strscpy(earlycon->name, name, min(len + 1, sizeof(earlycon->name)));
 	earlycon->data = &early_console_dev;
 }
 
@@ -123,7 +123,7 @@ static int __init parse_options(struct earlycon_device *device, char *options)
 		device->baud = simple_strtoul(options, NULL, 0);
 		length = min(strcspn(options, " ") + 1,
 			     (size_t)(sizeof(device->options)));
-		strlcpy(device->options, options, length);
+		strscpy(device->options, options, length);
 	}
 
 	return 0;
@@ -304,7 +304,7 @@ int __init of_setup_earlycon(const struct earlycon_id *match,
 
 	if (options) {
 		early_console_dev.baud = simple_strtoul(options, NULL, 0);
-		strlcpy(early_console_dev.options, options,
+		strscpy(early_console_dev.options, options,
 			sizeof(early_console_dev.options));
 	}
 	earlycon_init(&early_console_dev, match->name);
diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
index 98bb0c315e13..84e8153e5420 100644
--- a/drivers/tty/serial/fsl_linflexuart.c
+++ b/drivers/tty/serial/fsl_linflexuart.c
@@ -401,7 +401,7 @@ static void linflex_shutdown(struct uart_port *port)
 
 static void
 linflex_set_termios(struct uart_port *port, struct ktermios *termios,
-		    struct ktermios *old)
+		    const struct ktermios *old)
 {
 	unsigned long flags;
 	unsigned long cr, old_cr, cr1;
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index fbc4b071b330..67fa113f77d4 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1284,17 +1284,12 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
 	struct dma_slave_config dma_rx_sconfig = {};
 	struct circ_buf *ring = &sport->rx_ring;
 	int ret, nent;
-	int bits, baud;
 	struct tty_port *port = &sport->port.state->port;
 	struct tty_struct *tty = port->tty;
 	struct ktermios *termios = &tty->termios;
 	struct dma_chan *chan = sport->dma_rx_chan;
-
-	baud = tty_get_baud_rate(tty);
-
-	bits = (termios->c_cflag & CSIZE) == CS7 ? 9 : 10;
-	if (termios->c_cflag & PARENB)
-		bits++;
+	unsigned int bits = tty_get_frame_size(termios->c_cflag);
+	unsigned int baud = tty_get_baud_rate(tty);
 
 	/*
 	 * Calculate length of one DMA buffer size to keep latency below
@@ -1776,6 +1771,7 @@ static void lpuart_dma_shutdown(struct lpuart_port *sport)
 	if (sport->lpuart_dma_rx_use) {
 		del_timer_sync(&sport->lpuart_timer);
 		lpuart_dma_rx_free(&sport->port);
+		sport->lpuart_dma_rx_use = false;
 	}
 
 	if (sport->lpuart_dma_tx_use) {
@@ -1784,6 +1780,7 @@ static void lpuart_dma_shutdown(struct lpuart_port *sport)
 			sport->dma_tx_in_progress = false;
 			dmaengine_terminate_all(sport->dma_tx_chan);
 		}
+		sport->lpuart_dma_tx_use = false;
 	}
 
 	if (sport->dma_tx_chan)
@@ -1833,7 +1830,7 @@ static void lpuart32_shutdown(struct uart_port *port)
 
 static void
 lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
-		   struct ktermios *old)
+		   const struct ktermios *old)
 {
 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
 	unsigned long flags;
@@ -2073,7 +2070,7 @@ static void lpuart32_serial_setbrg(struct lpuart_port *sport,
 
 static void
 lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
-		   struct ktermios *old)
+		     const struct ktermios *old)
 {
 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
 	unsigned long flags;
@@ -2729,15 +2726,13 @@ static int lpuart_probe(struct platform_device *pdev)
 	if (ret)
 		goto failed_reset;
 
-	ret = uart_add_one_port(&lpuart_reg, &sport->port);
-	if (ret)
-		goto failed_attach_port;
-
 	ret = uart_get_rs485_mode(&sport->port);
 	if (ret)
 		goto failed_get_rs485;
 
-	uart_rs485_config(&sport->port);
+	ret = uart_add_one_port(&lpuart_reg, &sport->port);
+	if (ret)
+		goto failed_attach_port;
 
 	ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0,
 				DRIVER_NAME, sport);
@@ -2747,9 +2742,9 @@ static int lpuart_probe(struct platform_device *pdev)
 	return 0;
 
 failed_irq_request:
-failed_get_rs485:
 	uart_remove_one_port(&lpuart_reg, &sport->port);
 failed_attach_port:
+failed_get_rs485:
 failed_reset:
 	lpuart_disable_clks(sport);
 	return ret;
@@ -2800,7 +2795,7 @@ static int __maybe_unused lpuart_suspend(struct device *dev)
 		 * EDMA driver during suspend will forcefully release any
 		 * non-idle DMA channels. If port wakeup is enabled or if port
 		 * is console port or 'no_console_suspend' is set the Rx DMA
-		 * cannot resume as as expected, hence gracefully release the
+		 * cannot resume as expected, hence gracefully release the
 		 * Rx DMA path before suspend and start Rx DMA path on resume.
 		 */
 		if (irq_wake) {
diff --git a/drivers/tty/serial/icom.c b/drivers/tty/serial/icom.c
index 45df29947fe8..819f957b6b84 100644
--- a/drivers/tty/serial/icom.c
+++ b/drivers/tty/serial/icom.c
@@ -1351,9 +1351,8 @@ static void icom_close(struct uart_port *port)
 	kref_put(&icom_port->adapter->kref, icom_kref_release);
 }
 
-static void icom_set_termios(struct uart_port *port,
-			     struct ktermios *termios,
-			     struct ktermios *old_termios)
+static void icom_set_termios(struct uart_port *port, struct ktermios *termios,
+			     const struct ktermios *old_termios)
 {
 	struct icom_port *icom_port = to_icom_port(port);
 	int baud;
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 522445a8f666..05b432dc7a85 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -380,8 +380,7 @@ static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
 {
 	*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
 
-	sport->port.mctrl |= TIOCM_RTS;
-	mctrl_gpio_set(sport->gpios, sport->port.mctrl);
+	mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
 }
 
 /* called with port.lock taken and irqs caller dependent */
@@ -390,8 +389,7 @@ static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
 	*ucr2 &= ~UCR2_CTSC;
 	*ucr2 |= UCR2_CTS;
 
-	sport->port.mctrl &= ~TIOCM_RTS;
-	mctrl_gpio_set(sport->gpios, sport->port.mctrl);
+	mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
 }
 
 static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
@@ -1620,7 +1618,7 @@ static void imx_uart_flush_buffer(struct uart_port *port)
 
 static void
 imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
-		     struct ktermios *old)
+		     const struct ktermios *old)
 {
 	struct imx_port *sport = (struct imx_port *)port;
 	unsigned long flags;
@@ -2347,8 +2345,6 @@ static int imx_uart_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev,
 			"low-active RTS not possible when receiver is off, enabling receiver\n");
 
-	uart_rs485_config(&sport->port);
-
 	/* Disable interrupts before requesting them */
 	ucr1 = imx_uart_readl(sport, UCR1);
 	ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN | UCR1_RTSDEN);
diff --git a/drivers/tty/serial/ip22zilog.c b/drivers/tty/serial/ip22zilog.c
index 655e64b26852..dd0a8915ce4f 100644
--- a/drivers/tty/serial/ip22zilog.c
+++ b/drivers/tty/serial/ip22zilog.c
@@ -873,7 +873,7 @@ ip22zilog_convert_to_zs(struct uart_ip22zilog_port *up, unsigned int cflag,
 /* The port lock is not held.  */
 static void
 ip22zilog_set_termios(struct uart_port *port, struct ktermios *termios,
-		      struct ktermios *old)
+		      const struct ktermios *old)
 {
 	struct uart_ip22zilog_port *up =
 		container_of(port, struct uart_ip22zilog_port, port);
diff --git a/drivers/tty/serial/jsm/jsm_driver.c b/drivers/tty/serial/jsm/jsm_driver.c
index 0ea799bf8dbb..417a5b6bffc3 100644
--- a/drivers/tty/serial/jsm/jsm_driver.c
+++ b/drivers/tty/serial/jsm/jsm_driver.c
@@ -211,7 +211,8 @@ static int jsm_probe_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 		break;
 	default:
-		return -ENXIO;
+		rc = -ENXIO;
+		goto out_kfree_brd;
 	}
 
 	rc = request_irq(brd->irq, brd->bd_ops->intr, IRQF_SHARED, "JSM", brd);
diff --git a/drivers/tty/serial/jsm/jsm_tty.c b/drivers/tty/serial/jsm/jsm_tty.c
index cb58bdec2f43..222afc270c88 100644
--- a/drivers/tty/serial/jsm/jsm_tty.c
+++ b/drivers/tty/serial/jsm/jsm_tty.c
@@ -300,8 +300,8 @@ static void jsm_tty_close(struct uart_port *port)
 }
 
 static void jsm_tty_set_termios(struct uart_port *port,
-				 struct ktermios *termios,
-				 struct ktermios *old_termios)
+				struct ktermios *termios,
+				const struct ktermios *old_termios)
 {
 	unsigned long lock_flags;
 	struct jsm_channel *channel =
diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index a3120c3347dd..c892f3c7d1ab 100644
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -8,6 +8,7 @@
  * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/console.h>
 #include <linux/device.h>
@@ -93,7 +94,6 @@
 #define ASCFSTAT_RXFFLMASK	0x003F
 #define ASCFSTAT_TXFFLMASK	0x3F00
 #define ASCFSTAT_TXFREEMASK	0x3F000000
-#define ASCFSTAT_TXFREEOFF	24
 
 static void lqasc_tx_chars(struct uart_port *port);
 static struct ltq_uart_port *lqasc_port[MAXPORTS];
@@ -139,6 +139,13 @@ lqasc_stop_tx(struct uart_port *port)
 	return;
 }
 
+static bool lqasc_tx_ready(struct uart_port *port)
+{
+	u32 fstat = __raw_readl(port->membase + LTQ_ASC_FSTAT);
+
+	return FIELD_GET(ASCFSTAT_TXFREEMASK, fstat);
+}
+
 static void
 lqasc_start_tx(struct uart_port *port)
 {
@@ -228,8 +235,7 @@ lqasc_tx_chars(struct uart_port *port)
 		return;
 	}
 
-	while (((__raw_readl(port->membase + LTQ_ASC_FSTAT) &
-		ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF) != 0) {
+	while (lqasc_tx_ready(port)) {
 		if (port->x_char) {
 			writeb(port->x_char, port->membase + LTQ_ASC_TBUF);
 			port->icount.tx++;
@@ -405,8 +411,8 @@ lqasc_shutdown(struct uart_port *port)
 }
 
 static void
-lqasc_set_termios(struct uart_port *port,
-	struct ktermios *new, struct ktermios *old)
+lqasc_set_termios(struct uart_port *port, struct ktermios *new,
+		  const struct ktermios *old)
 {
 	unsigned int cflag;
 	unsigned int iflag;
@@ -600,15 +606,12 @@ static const struct uart_ops lqasc_pops = {
 static void
 lqasc_console_putchar(struct uart_port *port, unsigned char ch)
 {
-	int fifofree;
-
 	if (!port->membase)
 		return;
 
-	do {
-		fifofree = (__raw_readl(port->membase + LTQ_ASC_FSTAT)
-			& ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF;
-	} while (fifofree == 0);
+	while (!lqasc_tx_ready(port))
+		;
+
 	writeb(ch, port->membase + LTQ_ASC_TBUF);
 }
 
diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c
index 328b50521f14..4c0604325ee9 100644
--- a/drivers/tty/serial/liteuart.c
+++ b/drivers/tty/serial/liteuart.c
@@ -178,7 +178,7 @@ static void liteuart_shutdown(struct uart_port *port)
 }
 
 static void liteuart_set_termios(struct uart_port *port, struct ktermios *new,
-				 struct ktermios *old)
+				 const struct ktermios *old)
 {
 	unsigned int baud;
 	unsigned long flags;
diff --git a/drivers/tty/serial/lpc32xx_hs.c b/drivers/tty/serial/lpc32xx_hs.c
index 93140cac1ca1..ed47f4768338 100644
--- a/drivers/tty/serial/lpc32xx_hs.c
+++ b/drivers/tty/serial/lpc32xx_hs.c
@@ -278,6 +278,13 @@ static void __serial_lpc32xx_rx(struct uart_port *port)
 
 static void serial_lpc32xx_stop_tx(struct uart_port *port);
 
+static bool serial_lpc32xx_tx_ready(struct uart_port *port)
+{
+	u32 level = readl(LPC32XX_HSUART_LEVEL(port->membase));
+
+	return LPC32XX_HSU_TX_LEV(level) < 64;
+}
+
 static void __serial_lpc32xx_tx(struct uart_port *port)
 {
 	struct circ_buf *xmit = &port->state->xmit;
@@ -293,8 +300,7 @@ static void __serial_lpc32xx_tx(struct uart_port *port)
 		goto exit_tx;
 
 	/* Transfer data */
-	while (LPC32XX_HSU_TX_LEV(readl(
-		LPC32XX_HSUART_LEVEL(port->membase))) < 64) {
+	while (serial_lpc32xx_tx_ready(port)) {
 		writel((u32) xmit->buf[xmit->tail],
 		       LPC32XX_HSUART_FIFO(port->membase));
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
@@ -493,7 +499,7 @@ static void serial_lpc32xx_shutdown(struct uart_port *port)
 /* port->lock is not held.  */
 static void serial_lpc32xx_set_termios(struct uart_port *port,
 				       struct ktermios *termios,
-				       struct ktermios *old)
+				       const struct ktermios *old)
 {
 	unsigned long flags;
 	unsigned int baud, quot;
diff --git a/drivers/tty/serial/max3100.c b/drivers/tty/serial/max3100.c
index 0b5f21fbb53d..c69602f356fd 100644
--- a/drivers/tty/serial/max3100.c
+++ b/drivers/tty/serial/max3100.c
@@ -418,7 +418,7 @@ static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl)
 
 static void
 max3100_set_termios(struct uart_port *port, struct ktermios *termios,
-		    struct ktermios *old)
+		    const struct ktermios *old)
 {
 	struct max3100_port *s = container_of(port,
 					      struct max3100_port,
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 7cf81f692ac4..fbf6e2b3161c 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -906,7 +906,7 @@ static void max310x_break_ctl(struct uart_port *port, int break_state)
 
 static void max310x_set_termios(struct uart_port *port,
 				struct ktermios *termios,
-				struct ktermios *old)
+				const struct ktermios *old)
 {
 	unsigned int lcr = 0, flow = 0;
 	int baud;
diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c
index f4aaaadd0742..b1cd9a76dd93 100644
--- a/drivers/tty/serial/mcf.c
+++ b/drivers/tty/serial/mcf.c
@@ -192,7 +192,7 @@ static void mcf_shutdown(struct uart_port *port)
 /****************************************************************************/
 
 static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
-	struct ktermios *old)
+			    const struct ktermios *old)
 {
 	unsigned long flags;
 	unsigned int baud, baudclk;
diff --git a/drivers/tty/serial/men_z135_uart.c b/drivers/tty/serial/men_z135_uart.c
index 12117b596e73..3690f5cf0f43 100644
--- a/drivers/tty/serial/men_z135_uart.c
+++ b/drivers/tty/serial/men_z135_uart.c
@@ -646,8 +646,8 @@ static void men_z135_shutdown(struct uart_port *port)
 }
 
 static void men_z135_set_termios(struct uart_port *port,
-				struct ktermios *termios,
-				struct ktermios *old)
+				 struct ktermios *termios,
+				 const struct ktermios *old)
 {
 	struct men_z135_port *uart = to_men_z135(port);
 	unsigned int baud;
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index 6c8db19fd572..056243c12836 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -335,7 +335,7 @@ static void meson_uart_change_speed(struct uart_port *port, unsigned long baud)
 
 static void meson_uart_set_termios(struct uart_port *port,
 				   struct ktermios *termios,
-				   struct ktermios *old)
+				   const struct ktermios *old)
 {
 	unsigned int cflags, iflags, baud;
 	unsigned long flags;
@@ -667,29 +667,6 @@ static struct uart_driver meson_uart_driver = {
 	.cons		= MESON_SERIAL_CONSOLE,
 };
 
-static inline struct clk *meson_uart_probe_clock(struct device *dev,
-						 const char *id)
-{
-	struct clk *clk = NULL;
-	int ret;
-
-	clk = devm_clk_get(dev, id);
-	if (IS_ERR(clk))
-		return clk;
-
-	ret = clk_prepare_enable(clk);
-	if (ret) {
-		dev_err(dev, "couldn't enable clk\n");
-		return ERR_PTR(ret);
-	}
-
-	devm_add_action_or_reset(dev,
-			(void(*)(void *))clk_disable_unprepare,
-			clk);
-
-	return clk;
-}
-
 static int meson_uart_probe_clocks(struct platform_device *pdev,
 				   struct uart_port *port)
 {
@@ -697,15 +674,15 @@ static int meson_uart_probe_clocks(struct platform_device *pdev,
 	struct clk *clk_pclk = NULL;
 	struct clk *clk_baud = NULL;
 
-	clk_pclk = meson_uart_probe_clock(&pdev->dev, "pclk");
+	clk_pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
 	if (IS_ERR(clk_pclk))
 		return PTR_ERR(clk_pclk);
 
-	clk_xtal = meson_uart_probe_clock(&pdev->dev, "xtal");
+	clk_xtal = devm_clk_get_enabled(&pdev->dev, "xtal");
 	if (IS_ERR(clk_xtal))
 		return PTR_ERR(clk_xtal);
 
-	clk_baud = meson_uart_probe_clock(&pdev->dev, "baud");
+	clk_baud = devm_clk_get_enabled(&pdev->dev, "baud");
 	if (IS_ERR(clk_baud))
 		return PTR_ERR(clk_baud);
 
diff --git a/drivers/tty/serial/milbeaut_usio.c b/drivers/tty/serial/milbeaut_usio.c
index 347088bb380e..c15e0d84dc7e 100644
--- a/drivers/tty/serial/milbeaut_usio.c
+++ b/drivers/tty/serial/milbeaut_usio.c
@@ -298,7 +298,8 @@ static void mlb_usio_shutdown(struct uart_port *port)
 }
 
 static void mlb_usio_set_termios(struct uart_port *port,
-			struct ktermios *termios, struct ktermios *old)
+				 struct ktermios *termios,
+				 const struct ktermios *old)
 {
 	unsigned int escr, smr = MLB_USIO_SMR_SOE;
 	unsigned long flags, baud, quot;
diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c
index 3f1986c89694..73362d4bc45d 100644
--- a/drivers/tty/serial/mpc52xx_uart.c
+++ b/drivers/tty/serial/mpc52xx_uart.c
@@ -101,7 +101,7 @@ struct psc_ops {
 	void		(*cw_restore_ints)(struct uart_port *port);
 	unsigned int	(*set_baudrate)(struct uart_port *port,
 					struct ktermios *new,
-					struct ktermios *old);
+					const struct ktermios *old);
 	int		(*clock_alloc)(struct uart_port *port);
 	void		(*clock_relse)(struct uart_port *port);
 	int		(*clock)(struct uart_port *port, int enable);
@@ -287,7 +287,7 @@ static void mpc52xx_psc_cw_restore_ints(struct uart_port *port)
 
 static unsigned int mpc5200_psc_set_baudrate(struct uart_port *port,
 					     struct ktermios *new,
-					     struct ktermios *old)
+					     const struct ktermios *old)
 {
 	unsigned int baud;
 	unsigned int divisor;
@@ -305,7 +305,7 @@ static unsigned int mpc5200_psc_set_baudrate(struct uart_port *port,
 
 static unsigned int mpc5200b_psc_set_baudrate(struct uart_port *port,
 					      struct ktermios *new,
-					      struct ktermios *old)
+					      const struct ktermios *old)
 {
 	unsigned int baud;
 	unsigned int divisor;
@@ -533,7 +533,7 @@ static void mpc512x_psc_cw_restore_ints(struct uart_port *port)
 
 static unsigned int mpc512x_psc_set_baudrate(struct uart_port *port,
 					     struct ktermios *new,
-					     struct ktermios *old)
+					     const struct ktermios *old)
 {
 	unsigned int baud;
 	unsigned int divisor;
@@ -880,7 +880,7 @@ static inline void mpc5125_set_divisor(struct mpc5125_psc __iomem *psc,
 
 static unsigned int mpc5125_psc_set_baudrate(struct uart_port *port,
 					     struct ktermios *new,
-					     struct ktermios *old)
+					     const struct ktermios *old)
 {
 	unsigned int baud;
 	unsigned int divisor;
@@ -1167,7 +1167,7 @@ mpc52xx_uart_shutdown(struct uart_port *port)
 
 static void
 mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new,
-			 struct ktermios *old)
+			 const struct ktermios *old)
 {
 	unsigned long flags;
 	unsigned char mr1, mr2;
@@ -1364,7 +1364,7 @@ static const struct uart_ops mpc52xx_uart_ops = {
 /* Interrupt handling                                                       */
 /* ======================================================================== */
 
-static inline unsigned int
+static inline bool
 mpc52xx_uart_int_rx_chars(struct uart_port *port)
 {
 	struct tty_port *tport = &port->state->port;
@@ -1425,7 +1425,7 @@ mpc52xx_uart_int_rx_chars(struct uart_port *port)
 	return psc_ops->raw_rx_rdy(port);
 }
 
-static inline int
+static inline bool
 mpc52xx_uart_int_tx_chars(struct uart_port *port)
 {
 	struct circ_buf *xmit = &port->state->xmit;
@@ -1435,13 +1435,13 @@ mpc52xx_uart_int_tx_chars(struct uart_port *port)
 		psc_ops->write_char(port, port->x_char);
 		port->icount.tx++;
 		port->x_char = 0;
-		return 1;
+		return true;
 	}
 
 	/* Nothing to do ? */
 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
 		mpc52xx_uart_stop_tx(port);
-		return 0;
+		return false;
 	}
 
 	/* Send chars */
@@ -1460,23 +1460,23 @@ mpc52xx_uart_int_tx_chars(struct uart_port *port)
 	/* Maybe we're done after all */
 	if (uart_circ_empty(xmit)) {
 		mpc52xx_uart_stop_tx(port);
-		return 0;
+		return false;
 	}
 
-	return 1;
+	return true;
 }
 
 static irqreturn_t
 mpc5xxx_uart_process_int(struct uart_port *port)
 {
 	unsigned long pass = ISR_PASS_LIMIT;
-	unsigned int keepgoing;
+	bool keepgoing;
 	u8 status;
 
 	/* While we have stuff to do, we continue */
 	do {
 		/* If we don't find anything to do, we stop */
-		keepgoing = 0;
+		keepgoing = false;
 
 		psc_ops->rx_clr_irq(port);
 		if (psc_ops->rx_rdy(port))
@@ -1495,7 +1495,7 @@ mpc5xxx_uart_process_int(struct uart_port *port)
 
 		/* Limit number of iteration */
 		if (!(--pass))
-			keepgoing = 0;
+			keepgoing = false;
 
 	} while (keepgoing);
 
diff --git a/drivers/tty/serial/mps2-uart.c b/drivers/tty/serial/mps2-uart.c
index 5e9429dcc51f..2e3e6cf16817 100644
--- a/drivers/tty/serial/mps2-uart.c
+++ b/drivers/tty/serial/mps2-uart.c
@@ -358,7 +358,7 @@ static void mps2_uart_shutdown(struct uart_port *port)
 
 static void
 mps2_uart_set_termios(struct uart_port *port, struct ktermios *termios,
-		      struct ktermios *old)
+		      const struct ktermios *old)
 {
 	unsigned long flags;
 	unsigned int baud, bauddiv;
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index 3159889ddae1..7dd19a281579 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -1263,7 +1263,7 @@ static void msm_shutdown(struct uart_port *port)
 }
 
 static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
-			    struct ktermios *old)
+			    const struct ktermios *old)
 {
 	struct msm_port *msm_port = to_msm_port(port);
 	struct msm_dma *dma = &msm_port->rx_dma;
diff --git a/drivers/tty/serial/mux.c b/drivers/tty/serial/mux.c
index 0ba0f4d9459d..ed0e763f622a 100644
--- a/drivers/tty/serial/mux.c
+++ b/drivers/tty/serial/mux.c
@@ -289,7 +289,7 @@ static void mux_shutdown(struct uart_port *port)
  */
 static void
 mux_set_termios(struct uart_port *port, struct ktermios *termios,
-	        struct ktermios *old)
+	        const struct ktermios *old)
 {
 }
 
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
index 65eaecd10b7c..ba16e1da6bd3 100644
--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -564,7 +564,7 @@ static unsigned int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned in
 
 static void mvebu_uart_set_termios(struct uart_port *port,
 				   struct ktermios *termios,
-				   struct ktermios *old)
+				   const struct ktermios *old)
 {
 	unsigned long flags;
 	unsigned int baud, min_baud, max_baud;
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index 1944daf8593a..d21a4f3ef2fe 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -959,7 +959,7 @@ err_out:
 #define CTS_AT_AUART()	!mctrl_gpio_to_gpiod(s->gpios, UART_GPIO_CTS)
 static void mxs_auart_settermios(struct uart_port *u,
 				 struct ktermios *termios,
-				 struct ktermios *old)
+				 const struct ktermios *old)
 {
 	struct mxs_auart_port *s = to_auart_port(u);
 	u32 ctrl, ctrl2, div;
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 0aa666e247d5..7d0d2718ef59 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -300,8 +300,7 @@ static void serial_omap_stop_tx(struct uart_port *port)
 			serial_out(up, UART_OMAP_SCR, up->scr);
 			res = (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) ?
 				1 : 0;
-			if (up->rts_gpiod &&
-			    gpiod_get_value(up->rts_gpiod) != res) {
+			if (gpiod_get_value(up->rts_gpiod) != res) {
 				if (port->rs485.delay_rts_after_send > 0)
 					mdelay(
 					port->rs485.delay_rts_after_send);
@@ -337,19 +336,24 @@ static void serial_omap_stop_rx(struct uart_port *port)
 	serial_out(up, UART_IER, up->ier);
 }
 
+static void serial_omap_put_char(struct uart_omap_port *up, unsigned char ch)
+{
+	serial_out(up, UART_TX, ch);
+
+	if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
+			!(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
+		up->rs485_tx_filter_count++;
+}
+
 static void transmit_chars(struct uart_omap_port *up, unsigned int lsr)
 {
 	struct circ_buf *xmit = &up->port.state->xmit;
 	int count;
 
 	if (up->port.x_char) {
-		serial_out(up, UART_TX, up->port.x_char);
+		serial_omap_put_char(up, up->port.x_char);
 		up->port.icount.tx++;
 		up->port.x_char = 0;
-		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
-		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
-			up->rs485_tx_filter_count++;
-
 		return;
 	}
 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
@@ -358,12 +362,9 @@ static void transmit_chars(struct uart_omap_port *up, unsigned int lsr)
 	}
 	count = up->port.fifosize / 4;
 	do {
-		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+		serial_omap_put_char(up, xmit->buf[xmit->tail]);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 		up->port.icount.tx++;
-		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
-		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
-			up->rs485_tx_filter_count++;
 
 		if (uart_circ_empty(xmit))
 			break;
@@ -397,7 +398,7 @@ static void serial_omap_start_tx(struct uart_port *port)
 
 		/* if rts not already enabled */
 		res = (port->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0;
-		if (up->rts_gpiod && gpiod_get_value(up->rts_gpiod) != res) {
+		if (gpiod_get_value(up->rts_gpiod) != res) {
 			gpiod_set_value(up->rts_gpiod, res);
 			if (port->rs485.delay_rts_before_send > 0)
 				mdelay(port->rs485.delay_rts_before_send);
@@ -802,7 +803,7 @@ static void serial_omap_uart_qos_work(struct work_struct *work)
 
 static void
 serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
-			struct ktermios *old)
+			const struct ktermios *old)
 {
 	struct uart_omap_port *up = to_uart_omap_port(port);
 	unsigned char cval = 0;
@@ -1336,13 +1337,11 @@ serial_omap_config_rs485(struct uart_port *port, struct ktermios *termios,
 	up->ier = 0;
 	serial_out(up, UART_IER, 0);
 
-	if (up->rts_gpiod) {
-		/* enable / disable rts */
-		val = (rs485->flags & SER_RS485_ENABLED) ?
-			SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
-		val = (rs485->flags & val) ? 1 : 0;
-		gpiod_set_value(up->rts_gpiod, val);
-	}
+	/* enable / disable rts */
+	val = (rs485->flags & SER_RS485_ENABLED) ?
+	      SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
+	val = (rs485->flags & val) ? 1 : 0;
+	gpiod_set_value(up->rts_gpiod, val);
 
 	/* Enable interrupts */
 	up->ier = mode;
@@ -1547,11 +1546,13 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up,
 		ret = PTR_ERR(up->rts_gpiod);
 	        if (ret == -EPROBE_DEFER)
 			return ret;
-		/*
-		 * FIXME: the code historically ignored any other error than
-		 * -EPROBE_DEFER and just went on without GPIO.
-		 */
+
 		up->rts_gpiod = NULL;
+		up->port.rs485_supported = (const struct serial_rs485) { };
+		if (rs485conf->flags & SER_RS485_ENABLED) {
+			dev_err(dev, "disabling RS-485 (rts-gpio missing in device tree)\n");
+			memset(rs485conf, 0, sizeof(*rs485conf));
+		}
 	} else {
 		gpiod_set_consumer_name(up->rts_gpiod, "omap-serial");
 	}
diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c
index 888e17e3f25f..fde39cc1145d 100644
--- a/drivers/tty/serial/owl-uart.c
+++ b/drivers/tty/serial/owl-uart.c
@@ -328,7 +328,7 @@ static void owl_uart_change_baudrate(struct owl_uart_port *owl_port,
 
 static void owl_uart_set_termios(struct uart_port *port,
 				 struct ktermios *termios,
-				 struct ktermios *old)
+				 const struct ktermios *old)
 {
 	struct owl_uart_port *owl_port = to_owl_uart_port(port);
 	unsigned int baud;
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 8a9065e4a903..c59ce7886579 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -898,9 +898,7 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv)
 		fifo_size--;
 	}
 
-	bytes = min((int)CIRC_CNT(xmit->head, xmit->tail,
-			     UART_XMIT_SIZE), CIRC_CNT_TO_END(xmit->head,
-			     xmit->tail, UART_XMIT_SIZE));
+	bytes = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
 	if (!bytes) {
 		dev_dbg(priv->port.dev, "%s 0 bytes return\n", __func__);
 		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
@@ -1301,7 +1299,8 @@ static void pch_uart_shutdown(struct uart_port *port)
  *bits.  Update read_status_mask and ignore_status_mask to indicate
  *the types of events we are interested in receiving.  */
 static void pch_uart_set_termios(struct uart_port *port,
-				 struct ktermios *termios, struct ktermios *old)
+				 struct ktermios *termios,
+				 const struct ktermios *old)
 {
 	int rtn;
 	unsigned int baud, parity, bits, stb;
diff --git a/drivers/tty/serial/pic32_uart.c b/drivers/tty/serial/pic32_uart.c
index f418f1de66b3..2beada66c824 100644
--- a/drivers/tty/serial/pic32_uart.c
+++ b/drivers/tty/serial/pic32_uart.c
@@ -50,7 +50,7 @@
  * @irq_rx_name: irq rx name
  * @irq_tx: virtual tx interrupt number
  * @irq_tx_name: irq tx name
- * @cts_gpio: clear to send gpio
+ * @cts_gpiod: clear to send GPIO
  * @dev: device descriptor
  **/
 struct pic32_sport {
@@ -65,8 +65,7 @@ struct pic32_sport {
 	const char *irq_tx_name;
 	bool enable_tx_irq;
 
-	bool hw_flow_ctrl;
-	int cts_gpio;
+	struct gpio_desc *cts_gpiod;
 
 	struct clk *clk;
 
@@ -158,25 +157,16 @@ static void pic32_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 					PIC32_UART_MODE_LPBK);
 }
 
-/* get the state of CTS input pin for this port */
-static unsigned int get_cts_state(struct pic32_sport *sport)
-{
-	/* read and invert UxCTS */
-	if (gpio_is_valid(sport->cts_gpio))
-		return !gpio_get_value(sport->cts_gpio);
-
-	return 1;
-}
-
 /* serial core request to return the state of misc UART input pins */
 static unsigned int pic32_uart_get_mctrl(struct uart_port *port)
 {
 	struct pic32_sport *sport = to_pic32_sport(port);
 	unsigned int mctrl = 0;
 
-	if (!sport->hw_flow_ctrl)
+	/* get the state of CTS input pin for this port */
+	if (!sport->cts_gpiod)
 		mctrl |= TIOCM_CTS;
-	else if (get_cts_state(sport))
+	else if (gpiod_get_value(sport->cts_gpiod))
 		mctrl |= TIOCM_CTS;
 
 	/* DSR and CD are not supported in PIC32, so return 1
@@ -609,7 +599,7 @@ static void pic32_uart_shutdown(struct uart_port *port)
 /* serial core request to change current uart setting */
 static void pic32_uart_set_termios(struct uart_port *port,
 				   struct ktermios *new,
-				   struct ktermios *old)
+				   const struct ktermios *old)
 {
 	struct pic32_sport *sport = to_pic32_sport(port);
 	unsigned int baud;
@@ -648,7 +638,7 @@ static void pic32_uart_set_termios(struct uart_port *port,
 					PIC32_UART_MODE_PDSEL0);
 	}
 	/* if hw flow ctrl, then the pins must be specified in device tree */
-	if ((new->c_cflag & CRTSCTS) && sport->hw_flow_ctrl) {
+	if ((new->c_cflag & CRTSCTS) && sport->cts_gpiod) {
 		/* enable hardware flow control */
 		pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE),
 					PIC32_UART_MODE_UEN1);
@@ -875,7 +865,8 @@ static struct uart_driver pic32_uart_driver = {
 
 static int pic32_uart_probe(struct platform_device *pdev)
 {
-	struct device_node *np = pdev->dev.of_node;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
 	struct pic32_sport *sport;
 	int uart_idx = 0;
 	struct resource *res_mem;
@@ -904,25 +895,10 @@ static int pic32_uart_probe(struct platform_device *pdev)
 	/* Hardware flow control: gpios
 	 * !Note: Basically, CTS is needed for reading the status.
 	 */
-	sport->hw_flow_ctrl = false;
-	sport->cts_gpio = of_get_named_gpio(np, "cts-gpios", 0);
-	if (gpio_is_valid(sport->cts_gpio)) {
-		sport->hw_flow_ctrl = true;
-
-		ret = devm_gpio_request(sport->dev,
-					sport->cts_gpio, "CTS");
-		if (ret) {
-			dev_err(&pdev->dev,
-				"error requesting CTS GPIO\n");
-			goto err;
-		}
-
-		ret = gpio_direction_input(sport->cts_gpio);
-		if (ret) {
-			dev_err(&pdev->dev, "error setting CTS GPIO\n");
-			goto err;
-		}
-	}
+	sport->cts_gpiod = devm_gpiod_get_optional(dev, "cts", GPIOD_IN);
+	if (IS_ERR(sport->cts_gpiod))
+		return dev_err_probe(dev, PTR_ERR(sport->cts_gpiod), "error requesting CTS GPIO\n");
+	gpiod_set_consumer_name(sport->cts_gpiod, "CTS");
 
 	pic32_sports[uart_idx] = sport;
 	port = &sport->port;
@@ -943,7 +919,7 @@ static int pic32_uart_probe(struct platform_device *pdev)
 	}
 
 #ifdef CONFIG_SERIAL_PIC32_CONSOLE
-	if (uart_console(port) && (pic32_console.flags & CON_ENABLED)) {
+	if (uart_console_enabled(port)) {
 		/* The peripheral clock has been enabled by console_setup,
 		 * so disable it till the port is used.
 		 */
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index f63257b8e872..fe2e4ec423f7 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -1202,7 +1202,7 @@ static void pmz_irda_setup(struct uart_pmac_port *uap, unsigned long *baud)
 
 
 static void __pmz_set_termios(struct uart_port *port, struct ktermios *termios,
-			      struct ktermios *old)
+			      const struct ktermios *old)
 {
 	struct uart_pmac_port *uap = to_pmz(port);
 	unsigned long baud;
@@ -1244,7 +1244,7 @@ static void __pmz_set_termios(struct uart_port *port, struct ktermios *termios,
 
 /* The port lock is not held.  */
 static void pmz_set_termios(struct uart_port *port, struct ktermios *termios,
-			    struct ktermios *old)
+			    const struct ktermios *old)
 {
 	struct uart_pmac_port *uap = to_pmz(port);
 	unsigned long flags;
diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
index 9309ffd87c8e..2d25231fad84 100644
--- a/drivers/tty/serial/pxa.c
+++ b/drivers/tty/serial/pxa.c
@@ -423,7 +423,7 @@ static void serial_pxa_shutdown(struct uart_port *port)
 
 static void
 serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
-		       struct ktermios *old)
+		       const struct ktermios *old)
 {
 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
 	unsigned char cval, fcr = 0;
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index f4698a064a4d..83b66b73303a 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -22,6 +22,7 @@
 #include <linux/slab.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
+#include <dt-bindings/interconnect/qcom,icc.h>
 
 /* UART specific GENI registers */
 #define SE_UART_LOOPBACK_CFG		0x22c
@@ -1005,7 +1006,8 @@ static unsigned long get_clk_div_rate(struct clk *clk, unsigned int baud,
 }
 
 static void qcom_geni_serial_set_termios(struct uart_port *uport,
-				struct ktermios *termios, struct ktermios *old)
+					 struct ktermios *termios,
+					 const struct ktermios *old)
 {
 	unsigned int baud;
 	u32 bits_per_char;
@@ -1524,7 +1526,7 @@ static int __maybe_unused qcom_geni_serial_sys_suspend(struct device *dev)
 	 * even with no_console_suspend
 	 */
 	if (uart_console(uport)) {
-		geni_icc_set_tag(&port->se, 0x3);
+		geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ACTIVE_ONLY);
 		geni_icc_set_bw(&port->se);
 	}
 	return uart_suspend_port(private_data->drv, uport);
@@ -1539,7 +1541,7 @@ static int __maybe_unused qcom_geni_serial_sys_resume(struct device *dev)
 
 	ret = uart_resume_port(private_data->drv, uport);
 	if (uart_console(uport)) {
-		geni_icc_set_tag(&port->se, 0x7);
+		geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ALWAYS);
 		geni_icc_set_bw(&port->se);
 	}
 	return ret;
diff --git a/drivers/tty/serial/rda-uart.c b/drivers/tty/serial/rda-uart.c
index feb2054aba37..0e387e2144fa 100644
--- a/drivers/tty/serial/rda-uart.c
+++ b/drivers/tty/serial/rda-uart.c
@@ -238,7 +238,7 @@ static void rda_uart_change_baudrate(struct rda_uart_port *rda_port,
 
 static void rda_uart_set_termios(struct uart_port *port,
 				 struct ktermios *termios,
-				 struct ktermios *old)
+				 const struct ktermios *old)
 {
 	struct rda_uart_port *rda_port = to_rda_uart_port(port);
 	unsigned long flags;
diff --git a/drivers/tty/serial/rp2.c b/drivers/tty/serial/rp2.c
index 6689d8add8f7..b81afb06f1f4 100644
--- a/drivers/tty/serial/rp2.c
+++ b/drivers/tty/serial/rp2.c
@@ -370,9 +370,8 @@ static void __rp2_uart_set_termios(struct rp2_uart_port *up,
 	       up->ucode + RP2_RX_SWFLOW);
 }
 
-static void rp2_uart_set_termios(struct uart_port *port,
-				 struct ktermios *new,
-				 struct ktermios *old)
+static void rp2_uart_set_termios(struct uart_port *port, struct ktermios *new,
+				 const struct ktermios *old)
 {
 	struct rp2_uart_port *up = port_to_up(port);
 	unsigned long flags;
diff --git a/drivers/tty/serial/sa1100.c b/drivers/tty/serial/sa1100.c
index e64e42a19d1a..dd9e3253cab4 100644
--- a/drivers/tty/serial/sa1100.c
+++ b/drivers/tty/serial/sa1100.c
@@ -409,7 +409,7 @@ static void sa1100_shutdown(struct uart_port *port)
 
 static void
 sa1100_set_termios(struct uart_port *port, struct ktermios *termios,
-		   struct ktermios *old)
+		   const struct ktermios *old)
 {
 	struct sa1100_port *sport =
 		container_of(port, struct sa1100_port, port);
diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index b7a4b47ce74e..77d1363029f5 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1530,7 +1530,7 @@ static const u16 udivslot_table[16] = {
 
 static void s3c24xx_serial_set_termios(struct uart_port *port,
 				       struct ktermios *termios,
-				       struct ktermios *old)
+				       const struct ktermios *old)
 {
 	const struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port);
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
diff --git a/drivers/tty/serial/sb1250-duart.c b/drivers/tty/serial/sb1250-duart.c
index 2cf8533ef760..c5d2b6cdcb4a 100644
--- a/drivers/tty/serial/sb1250-duart.c
+++ b/drivers/tty/serial/sb1250-duart.c
@@ -531,7 +531,7 @@ static void sbd_init_port(struct sbd_port *sport)
 }
 
 static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
-			    struct ktermios *old_termios)
+			    const struct ktermios *old_termios)
 {
 	struct sbd_port *sport = to_sport(uport);
 	unsigned int mode1 = 0, mode2 = 0, aux = 0;
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index d983692c59e0..524921360ca7 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1015,7 +1015,7 @@ static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
 
 static void sc16is7xx_set_termios(struct uart_port *port,
 				  struct ktermios *termios,
-				  struct ktermios *old)
+				  const struct ktermios *old)
 {
 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
index c56de2e104d4..dd98509f52e5 100644
--- a/drivers/tty/serial/sccnxp.c
+++ b/drivers/tty/serial/sccnxp.c
@@ -636,7 +636,8 @@ static void sccnxp_break_ctl(struct uart_port *port, int break_state)
 }
 
 static void sccnxp_set_termios(struct uart_port *port,
-			       struct ktermios *termios, struct ktermios *old)
+			       struct ktermios *termios,
+			       const struct ktermios *old)
 {
 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
 	unsigned long flags;
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index a5748e41483b..b7170cb9a544 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -1270,14 +1270,14 @@ static void tegra_uart_enable_ms(struct uart_port *u)
 }
 
 static void tegra_uart_set_termios(struct uart_port *u,
-		struct ktermios *termios, struct ktermios *oldtermios)
+				   struct ktermios *termios,
+				   const struct ktermios *oldtermios)
 {
 	struct tegra_uart_port *tup = to_tegra_uport(u);
 	unsigned int baud;
 	unsigned long flags;
 	unsigned int lcr;
 	unsigned char char_bits;
-	int symb_bit = 1;
 	struct clk *parent_clk = clk_get_parent(tup->uart_clk);
 	unsigned long parent_clk_rate = clk_get_rate(parent_clk);
 	int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF;
@@ -1304,7 +1304,6 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	termios->c_cflag &= ~CMSPAR;
 
 	if ((termios->c_cflag & PARENB) == PARENB) {
-		symb_bit++;
 		if (termios->c_cflag & PARODD) {
 			lcr |= UART_LCR_PARITY;
 			lcr &= ~UART_LCR_EPAR;
@@ -1317,22 +1316,18 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	}
 
 	char_bits = tty_get_char_size(termios->c_cflag);
-	symb_bit += char_bits;
 	lcr &= ~UART_LCR_WLEN8;
 	lcr |= UART_LCR_WLEN(char_bits);
 
 	/* Stop bits */
-	if (termios->c_cflag & CSTOPB) {
+	if (termios->c_cflag & CSTOPB)
 		lcr |= UART_LCR_STOP;
-		symb_bit += 2;
-	} else {
+	else
 		lcr &= ~UART_LCR_STOP;
-		symb_bit++;
-	}
 
 	tegra_uart_write(tup, lcr, UART_LCR);
 	tup->lcr_shadow = lcr;
-	tup->symb_bit = symb_bit;
+	tup->symb_bit = tty_get_frame_size(termios->c_cflag);
 
 	/* Baud rate. */
 	baud = uart_get_baud_rate(u, termios, oldtermios,
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 12c87cd201a7..179ee199df34 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -49,7 +49,7 @@ static struct lock_class_key port_lock_key;
 #define RS485_MAX_RTS_DELAY	100 /* msecs */
 
 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
-					struct ktermios *old_termios);
+			      const struct ktermios *old_termios);
 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
 static void uart_change_pm(struct uart_state *state,
 			   enum uart_pm_state pm_state);
@@ -158,15 +158,10 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
 	unsigned long flags;
 	unsigned int old;
 
-	if (port->rs485.flags & SER_RS485_ENABLED) {
-		set &= ~TIOCM_RTS;
-		clear &= ~TIOCM_RTS;
-	}
-
 	spin_lock_irqsave(&port->lock, flags);
 	old = port->mctrl;
 	port->mctrl = (old & ~clear) | set;
-	if (old != port->mctrl)
+	if (old != port->mctrl && !(port->rs485.flags & SER_RS485_ENABLED))
 		port->ops->set_mctrl(port, port->mctrl);
 	spin_unlock_irqrestore(&port->lock, flags);
 }
@@ -380,7 +375,7 @@ EXPORT_SYMBOL(uart_update_timeout);
  */
 unsigned int
 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
-		   struct ktermios *old, unsigned int min, unsigned int max)
+		   const struct ktermios *old, unsigned int min, unsigned int max)
 {
 	unsigned int try;
 	unsigned int baud;
@@ -492,7 +487,7 @@ EXPORT_SYMBOL(uart_get_divisor);
 
 /* Caller holds port mutex */
 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
-					struct ktermios *old_termios)
+			      const struct ktermios *old_termios)
 {
 	struct uart_port *uport = uart_port_check(state);
 	struct ktermios *termios;
@@ -1391,7 +1386,7 @@ static void uart_set_rs485_termination(struct uart_port *port,
 				 !!(rs485->flags & SER_RS485_TERMINATE_BUS));
 }
 
-int uart_rs485_config(struct uart_port *port)
+static int uart_rs485_config(struct uart_port *port)
 {
 	struct serial_rs485 *rs485 = &port->rs485;
 	int ret;
@@ -1405,7 +1400,6 @@ int uart_rs485_config(struct uart_port *port)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(uart_rs485_config);
 
 static int uart_get_rs485_config(struct uart_port *port,
 			 struct serial_rs485 __user *rs485)
@@ -1444,8 +1438,13 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
 
 	spin_lock_irqsave(&port->lock, flags);
 	ret = port->rs485_config(port, &tty->termios, &rs485);
-	if (!ret)
+	if (!ret) {
 		port->rs485 = rs485;
+
+		/* Reset RTS and other mctrl lines when disabling RS485 */
+		if (!(rs485.flags & SER_RS485_ENABLED))
+			port->ops->set_mctrl(port, port->mctrl);
+	}
 	spin_unlock_irqrestore(&port->lock, flags);
 	if (ret)
 		return ret;
@@ -1619,7 +1618,7 @@ static void uart_set_ldisc(struct tty_struct *tty)
 }
 
 static void uart_set_termios(struct tty_struct *tty,
-						struct ktermios *old_termios)
+			     const struct ktermios *old_termios)
 {
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *uport;
@@ -2352,7 +2351,8 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 
 		spin_lock_irq(&uport->lock);
 		ops->stop_tx(uport);
-		ops->set_mctrl(uport, 0);
+		if (!(uport->rs485.flags & SER_RS485_ENABLED))
+			ops->set_mctrl(uport, 0);
 		/* save mctrl so it can be restored on resume */
 		mctrl = uport->mctrl;
 		uport->mctrl = 0;
@@ -2440,7 +2440,8 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 
 		uart_change_pm(state, UART_PM_STATE_ON);
 		spin_lock_irq(&uport->lock);
-		ops->set_mctrl(uport, 0);
+		if (!(uport->rs485.flags & SER_RS485_ENABLED))
+			ops->set_mctrl(uport, 0);
 		spin_unlock_irq(&uport->lock);
 		if (console_suspend_enabled || !uart_console(uport)) {
 			/* Protected by port mutex for now */
@@ -2451,7 +2452,10 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 				if (tty)
 					uart_change_speed(tty, state, NULL);
 				spin_lock_irq(&uport->lock);
-				ops->set_mctrl(uport, uport->mctrl);
+				if (!(uport->rs485.flags & SER_RS485_ENABLED))
+					ops->set_mctrl(uport, uport->mctrl);
+				else
+					uart_rs485_config(uport);
 				ops->start_tx(uport);
 				spin_unlock_irq(&uport->lock);
 				tty_port_set_initialized(port, 1);
@@ -2497,7 +2501,7 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port)
 			 "MMIO 0x%llx", (unsigned long long)port->mapbase);
 		break;
 	default:
-		strlcpy(address, "*unknown*", sizeof(address));
+		strscpy(address, "*unknown*", sizeof(address));
 		break;
 	}
 
@@ -2558,10 +2562,10 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		 */
 		spin_lock_irqsave(&port->lock, flags);
 		port->mctrl &= TIOCM_DTR;
-		if (port->rs485.flags & SER_RS485_ENABLED &&
-		    !(port->rs485.flags & SER_RS485_RTS_AFTER_SEND))
-			port->mctrl |= TIOCM_RTS;
-		port->ops->set_mctrl(port, port->mctrl);
+		if (!(port->rs485.flags & SER_RS485_ENABLED))
+			port->ops->set_mctrl(port, port->mctrl);
+		else
+			uart_rs485_config(port);
 		spin_unlock_irqrestore(&port->lock, flags);
 
 		/*
diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c
index 228e380db080..e12f1dc18c38 100644
--- a/drivers/tty/serial/serial_txx9.c
+++ b/drivers/tty/serial/serial_txx9.c
@@ -594,7 +594,7 @@ static void serial_txx9_shutdown(struct uart_port *up)
 
 static void
 serial_txx9_set_termios(struct uart_port *up, struct ktermios *termios,
-		       struct ktermios *old)
+			const struct ktermios *old)
 {
 	unsigned int cval, fcr = 0;
 	unsigned long flags;
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 0075a1420005..62f773286d44 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1407,10 +1407,8 @@ static void sci_dma_tx_work_fn(struct work_struct *work)
 	spin_lock_irq(&port->lock);
 	head = xmit->head;
 	tail = xmit->tail;
-	buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
-	s->tx_dma_len = min_t(unsigned int,
-		CIRC_CNT(head, tail, UART_XMIT_SIZE),
-		CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
+	buf = s->tx_dma_addr + tail;
+	s->tx_dma_len = CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE);
 	if (!s->tx_dma_len) {
 		/* Transmit buffer has been flushed */
 		spin_unlock_irq(&port->lock);
@@ -2367,7 +2365,7 @@ static void sci_reset(struct uart_port *port)
 }
 
 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
-			    struct ktermios *old)
+		            const struct ktermios *old)
 {
 	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
 	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c
index 4b1d4fe8458e..7fb6760b5c37 100644
--- a/drivers/tty/serial/sifive.c
+++ b/drivers/tty/serial/sifive.c
@@ -646,7 +646,7 @@ static int sifive_serial_clk_notifier(struct notifier_block *nb,
 
 static void sifive_serial_set_termios(struct uart_port *port,
 				      struct ktermios *termios,
-				      struct ktermios *old)
+				      const struct ktermios *old)
 {
 	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
 	unsigned long flags;
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
index 4329b9c9cbf0..342a87967631 100644
--- a/drivers/tty/serial/sprd_serial.c
+++ b/drivers/tty/serial/sprd_serial.c
@@ -771,9 +771,8 @@ static void sprd_shutdown(struct uart_port *port)
 	devm_free_irq(port->dev, port->irq, port);
 }
 
-static void sprd_set_termios(struct uart_port *port,
-			     struct ktermios *termios,
-			     struct ktermios *old)
+static void sprd_set_termios(struct uart_port *port, struct ktermios *termios,
+		             const struct ktermios *old)
 {
 	unsigned int baud, quot;
 	unsigned int lcr = 0, fc;
diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
index cce42f4c9bc2..fcecea689a0d 100644
--- a/drivers/tty/serial/st-asc.c
+++ b/drivers/tty/serial/st-asc.c
@@ -500,7 +500,7 @@ static void asc_pm(struct uart_port *port, unsigned int state,
 }
 
 static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
-			    struct ktermios *old)
+			    const struct ktermios *old)
 {
 	struct asc_port *ascport = to_asc_port(port);
 	struct gpio_desc *gpiod;
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 2c85dbf165c4..dfdbcf092fac 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -37,7 +37,7 @@
 
 
 /* Register offsets */
-static struct stm32_usart_info stm32f4_info = {
+static struct stm32_usart_info __maybe_unused stm32f4_info = {
 	.ofs = {
 		.isr	= 0x00,
 		.rdr	= 0x04,
@@ -58,7 +58,7 @@ static struct stm32_usart_info stm32f4_info = {
 	}
 };
 
-static struct stm32_usart_info stm32f7_info = {
+static struct stm32_usart_info __maybe_unused stm32f7_info = {
 	.ofs = {
 		.cr1	= 0x00,
 		.cr2	= 0x04,
@@ -80,7 +80,7 @@ static struct stm32_usart_info stm32f7_info = {
 	}
 };
 
-static struct stm32_usart_info stm32h7_info = {
+static struct stm32_usart_info __maybe_unused stm32h7_info = {
 	.ofs = {
 		.cr1	= 0x00,
 		.cr2	= 0x04,
@@ -131,6 +131,53 @@ static void stm32_usart_clr_bits(struct uart_port *port, u32 reg, u32 bits)
 	writel_relaxed(val, port->membase + reg);
 }
 
+static unsigned int stm32_usart_tx_empty(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	if (readl_relaxed(port->membase + ofs->isr) & USART_SR_TC)
+		return TIOCSER_TEMT;
+
+	return 0;
+}
+
+static void stm32_usart_rs485_rts_enable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct serial_rs485 *rs485conf = &port->rs485;
+
+	if (stm32_port->hw_flow_control ||
+	    !(rs485conf->flags & SER_RS485_ENABLED))
+		return;
+
+	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl | TIOCM_RTS);
+	} else {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl & ~TIOCM_RTS);
+	}
+}
+
+static void stm32_usart_rs485_rts_disable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct serial_rs485 *rs485conf = &port->rs485;
+
+	if (stm32_port->hw_flow_control ||
+	    !(rs485conf->flags & SER_RS485_ENABLED))
+		return;
+
+	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl & ~TIOCM_RTS);
+	} else {
+		mctrl_gpio_set(stm32_port->gpios,
+			       stm32_port->port.mctrl | TIOCM_RTS);
+	}
+}
+
 static void stm32_usart_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE,
 					 u32 delay_DDE, u32 baud)
 {
@@ -214,6 +261,12 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter
 
 	stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
 
+	/* Adjust RTS polarity in case it's driven in software */
+	if (stm32_usart_tx_empty(port))
+		stm32_usart_rs485_rts_disable(port);
+	else
+		stm32_usart_rs485_rts_enable(port);
+
 	return 0;
 }
 
@@ -529,42 +582,6 @@ static void stm32_usart_tc_interrupt_disable(struct uart_port *port)
 	stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TCIE);
 }
 
-static void stm32_usart_rs485_rts_enable(struct uart_port *port)
-{
-	struct stm32_port *stm32_port = to_stm32_port(port);
-	struct serial_rs485 *rs485conf = &port->rs485;
-
-	if (stm32_port->hw_flow_control ||
-	    !(rs485conf->flags & SER_RS485_ENABLED))
-		return;
-
-	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
-		mctrl_gpio_set(stm32_port->gpios,
-			       stm32_port->port.mctrl | TIOCM_RTS);
-	} else {
-		mctrl_gpio_set(stm32_port->gpios,
-			       stm32_port->port.mctrl & ~TIOCM_RTS);
-	}
-}
-
-static void stm32_usart_rs485_rts_disable(struct uart_port *port)
-{
-	struct stm32_port *stm32_port = to_stm32_port(port);
-	struct serial_rs485 *rs485conf = &port->rs485;
-
-	if (stm32_port->hw_flow_control ||
-	    !(rs485conf->flags & SER_RS485_ENABLED))
-		return;
-
-	if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
-		mctrl_gpio_set(stm32_port->gpios,
-			       stm32_port->port.mctrl & ~TIOCM_RTS);
-	} else {
-		mctrl_gpio_set(stm32_port->gpios,
-			       stm32_port->port.mctrl | TIOCM_RTS);
-	}
-}
-
 static void stm32_usart_transmit_chars_pio(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -807,17 +824,6 @@ static irqreturn_t stm32_usart_threaded_interrupt(int irq, void *ptr)
 	return IRQ_HANDLED;
 }
 
-static unsigned int stm32_usart_tx_empty(struct uart_port *port)
-{
-	struct stm32_port *stm32_port = to_stm32_port(port);
-	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
-
-	if (readl_relaxed(port->membase + ofs->isr) & USART_SR_TC)
-		return TIOCSER_TEMT;
-
-	return 0;
-}
-
 static void stm32_usart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
@@ -1089,7 +1095,7 @@ static void stm32_usart_shutdown(struct uart_port *port)
 
 static void stm32_usart_set_termios(struct uart_port *port,
 				    struct ktermios *termios,
-				    struct ktermios *old)
+				    const struct ktermios *old)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
diff --git a/drivers/tty/serial/sunhv.c b/drivers/tty/serial/sunhv.c
index eafada8fb6fa..1938ba5e98c0 100644
--- a/drivers/tty/serial/sunhv.c
+++ b/drivers/tty/serial/sunhv.c
@@ -323,7 +323,7 @@ static void sunhv_shutdown(struct uart_port *port)
 
 /* port->lock is not held.  */
 static void sunhv_set_termios(struct uart_port *port, struct ktermios *termios,
-			      struct ktermios *old)
+			      const struct ktermios *old)
 {
 	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 	unsigned int quot = uart_get_divisor(port, baud);
diff --git a/drivers/tty/serial/sunplus-uart.c b/drivers/tty/serial/sunplus-uart.c
index 60c73662f955..7afe61a0e72e 100644
--- a/drivers/tty/serial/sunplus-uart.c
+++ b/drivers/tty/serial/sunplus-uart.c
@@ -333,7 +333,7 @@ static void sunplus_shutdown(struct uart_port *port)
 
 static void sunplus_set_termios(struct uart_port *port,
 				struct ktermios *termios,
-				struct ktermios *oldtermios)
+				const struct ktermios *oldtermios)
 {
 	u32 ext, div, div_l, div_h, baud, lcr;
 	u32 clk = port->uartclk;
diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
index 6ea52293d9f3..99608b2a2b74 100644
--- a/drivers/tty/serial/sunsab.c
+++ b/drivers/tty/serial/sunsab.c
@@ -681,27 +681,23 @@ static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cfla
 				  unsigned int quot)
 {
 	unsigned char dafo;
-	int bits, n, m;
+	int n, m;
 
 	/* Byte size and parity */
 	switch (cflag & CSIZE) {
-	      case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
-	      case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
-	      case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
-	      case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
+	      case CS5: dafo = SAB82532_DAFO_CHL5; break;
+	      case CS6: dafo = SAB82532_DAFO_CHL6; break;
+	      case CS7: dafo = SAB82532_DAFO_CHL7; break;
+	      case CS8: dafo = SAB82532_DAFO_CHL8; break;
 	      /* Never happens, but GCC is too dumb to figure it out */
-	      default:  dafo = SAB82532_DAFO_CHL5; bits = 7; break;
+	      default:  dafo = SAB82532_DAFO_CHL5; break;
 	}
 
-	if (cflag & CSTOPB) {
+	if (cflag & CSTOPB)
 		dafo |= SAB82532_DAFO_STOP;
-		bits++;
-	}
 
-	if (cflag & PARENB) {
+	if (cflag & PARENB)
 		dafo |= SAB82532_DAFO_PARE;
-		bits++;
-	}
 
 	if (cflag & PARODD) {
 		dafo |= SAB82532_DAFO_PAR_ODD;
@@ -776,7 +772,7 @@ static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cfla
 
 /* port->lock is not held.  */
 static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
-			       struct ktermios *old)
+			       const struct ktermios *old)
 {
 	struct uart_sunsab_port *up =
 		container_of(port, struct uart_sunsab_port, port);
diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index 84d545e5a8c7..9ea7e567540d 100644
--- a/drivers/tty/serial/sunsu.c
+++ b/drivers/tty/serial/sunsu.c
@@ -897,7 +897,7 @@ sunsu_change_speed(struct uart_port *port, unsigned int cflag,
 
 static void
 sunsu_set_termios(struct uart_port *port, struct ktermios *termios,
-		  struct ktermios *old)
+		  const struct ktermios *old)
 {
 	unsigned int baud, quot;
 
@@ -1217,13 +1217,13 @@ static int sunsu_kbd_ms_init(struct uart_sunsu_port *up)
 	serio->id.type = SERIO_RS232;
 	if (up->su_type == SU_PORT_KBD) {
 		serio->id.proto = SERIO_SUNKBD;
-		strlcpy(serio->name, "sukbd", sizeof(serio->name));
+		strscpy(serio->name, "sukbd", sizeof(serio->name));
 	} else {
 		serio->id.proto = SERIO_SUN;
 		serio->id.extra = 1;
-		strlcpy(serio->name, "sums", sizeof(serio->name));
+		strscpy(serio->name, "sums", sizeof(serio->name));
 	}
-	strlcpy(serio->phys,
+	strscpy(serio->phys,
 		(!(up->port.line & 1) ? "su/serio0" : "su/serio1"),
 		sizeof(serio->phys));
 
diff --git a/drivers/tty/serial/sunzilog.c b/drivers/tty/serial/sunzilog.c
index c14275d83b0b..87425290687d 100644
--- a/drivers/tty/serial/sunzilog.c
+++ b/drivers/tty/serial/sunzilog.c
@@ -938,7 +938,7 @@ sunzilog_convert_to_zs(struct uart_sunzilog_port *up, unsigned int cflag,
 /* The port lock is not held.  */
 static void
 sunzilog_set_termios(struct uart_port *port, struct ktermios *termios,
-		     struct ktermios *old)
+		     const struct ktermios *old)
 {
 	struct uart_sunzilog_port *up =
 		container_of(port, struct uart_sunzilog_port, port);
@@ -1307,13 +1307,13 @@ static void sunzilog_register_serio(struct uart_sunzilog_port *up)
 	serio->id.type = SERIO_RS232;
 	if (up->flags & SUNZILOG_FLAG_CONS_KEYB) {
 		serio->id.proto = SERIO_SUNKBD;
-		strlcpy(serio->name, "zskbd", sizeof(serio->name));
+		strscpy(serio->name, "zskbd", sizeof(serio->name));
 	} else {
 		serio->id.proto = SERIO_SUN;
 		serio->id.extra = 1;
-		strlcpy(serio->name, "zsms", sizeof(serio->name));
+		strscpy(serio->name, "zsms", sizeof(serio->name));
 	}
-	strlcpy(serio->phys,
+	strscpy(serio->phys,
 		((up->flags & SUNZILOG_FLAG_CONS_KEYB) ?
 		 "zs/serio0" : "zs/serio1"),
 		sizeof(serio->phys));
diff --git a/drivers/tty/serial/tegra-tcu.c b/drivers/tty/serial/tegra-tcu.c
index 889b701ba7c6..23500b342da7 100644
--- a/drivers/tty/serial/tegra-tcu.c
+++ b/drivers/tty/serial/tegra-tcu.c
@@ -126,7 +126,7 @@ static void tegra_tcu_uart_shutdown(struct uart_port *port)
 
 static void tegra_tcu_uart_set_termios(struct uart_port *port,
 				       struct ktermios *new,
-				       struct ktermios *old)
+				       const struct ktermios *old)
 {
 }
 
diff --git a/drivers/tty/serial/timbuart.c b/drivers/tty/serial/timbuart.c
index 08941eabe7b1..bb19ed012def 100644
--- a/drivers/tty/serial/timbuart.c
+++ b/drivers/tty/serial/timbuart.c
@@ -275,8 +275,8 @@ static int get_bindex(int baud)
 }
 
 static void timbuart_set_termios(struct uart_port *port,
-	struct ktermios *termios,
-	struct ktermios *old)
+				 struct ktermios *termios,
+				 const struct ktermios *old)
 {
 	unsigned int baud;
 	short bindex;
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index 880e2afbb97b..eca41ac5477c 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -314,8 +314,9 @@ static void ulite_shutdown(struct uart_port *port)
 	clk_disable(pdata->clk);
 }
 
-static void ulite_set_termios(struct uart_port *port, struct ktermios *termios,
-			      struct ktermios *old)
+static void ulite_set_termios(struct uart_port *port,
+			      struct ktermios *termios,
+			      const struct ktermios *old)
 {
 	unsigned long flags;
 	struct uartlite_data *pdata = port->private_data;
diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
index 3cc9ef08455c..82cf14dd3d43 100644
--- a/drivers/tty/serial/ucc_uart.c
+++ b/drivers/tty/serial/ucc_uart.c
@@ -843,7 +843,8 @@ static void qe_uart_shutdown(struct uart_port *port)
  * Set the serial port parameters.
  */
 static void qe_uart_set_termios(struct uart_port *port,
-				struct ktermios *termios, struct ktermios *old)
+				struct ktermios *termios,
+				const struct ktermios *old)
 {
 	struct uart_qe_port *qe_port =
 		container_of(port, struct uart_qe_port, port);
@@ -853,13 +854,6 @@ static void qe_uart_set_termios(struct uart_port *port,
 	u16 upsmr = ioread16be(&uccp->upsmr);
 	struct ucc_uart_pram __iomem *uccup = qe_port->uccup;
 	u16 supsmr = ioread16be(&uccup->supsmr);
-	u8 char_length = 2; /* 1 + CL + PEN + 1 + SL */
-
-	/* Character length programmed into the mode register is the
-	 * sum of: 1 start bit, number of data bits, 0 or 1 parity bit,
-	 * 1 or 2 stop bits, minus 1.
-	 * The value 'bits' counts this for us.
-	 */
 
 	/* byte size */
 	upsmr &= UCC_UART_UPSMR_CL_MASK;
@@ -869,22 +863,18 @@ static void qe_uart_set_termios(struct uart_port *port,
 	case CS5:
 		upsmr |= UCC_UART_UPSMR_CL_5;
 		supsmr |= UCC_UART_SUPSMR_CL_5;
-		char_length += 5;
 		break;
 	case CS6:
 		upsmr |= UCC_UART_UPSMR_CL_6;
 		supsmr |= UCC_UART_SUPSMR_CL_6;
-		char_length += 6;
 		break;
 	case CS7:
 		upsmr |= UCC_UART_UPSMR_CL_7;
 		supsmr |= UCC_UART_SUPSMR_CL_7;
-		char_length += 7;
 		break;
 	default:	/* case CS8 */
 		upsmr |= UCC_UART_UPSMR_CL_8;
 		supsmr |= UCC_UART_SUPSMR_CL_8;
-		char_length += 8;
 		break;
 	}
 
@@ -892,13 +882,11 @@ static void qe_uart_set_termios(struct uart_port *port,
 	if (termios->c_cflag & CSTOPB) {
 		upsmr |= UCC_UART_UPSMR_SL;
 		supsmr |= UCC_UART_SUPSMR_SL;
-		char_length++;  /* + SL */
 	}
 
 	if (termios->c_cflag & PARENB) {
 		upsmr |= UCC_UART_UPSMR_PEN;
 		supsmr |= UCC_UART_SUPSMR_PEN;
-		char_length++;  /* + PEN */
 
 		if (!(termios->c_cflag & PARODD)) {
 			upsmr &= ~(UCC_UART_UPSMR_RPM_MASK |
@@ -953,7 +941,7 @@ static void qe_uart_set_termios(struct uart_port *port,
 	iowrite16be(upsmr, &uccp->upsmr);
 	if (soft_uart) {
 		iowrite16be(supsmr, &uccup->supsmr);
-		iowrite8(char_length, &uccup->rx_length);
+		iowrite8(tty_get_frame_size(termios->c_cflag), &uccup->rx_length);
 
 		/* Soft-UART requires a 1X multiplier for TX */
 		qe_setbrg(qe_port->us_info.rx_clock, baud, 16);
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index 6f08136ce78a..10fbdb09965f 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -187,6 +187,13 @@ static void handle_rx(struct uart_port *port)
 	tty_flip_buffer_push(tport);
 }
 
+static unsigned int vt8500_tx_empty(struct uart_port *port)
+{
+	unsigned int idx = vt8500_read(port, VT8500_URFIDX) & 0x1f;
+
+	return idx < 16 ? TIOCSER_TEMT : 0;
+}
+
 static void handle_tx(struct uart_port *port)
 {
 	struct circ_buf *xmit = &port->state->xmit;
@@ -201,7 +208,7 @@ static void handle_tx(struct uart_port *port)
 		return;
 	}
 
-	while ((vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16) {
+	while (vt8500_tx_empty(port)) {
 		if (uart_circ_empty(xmit))
 			break;
 
@@ -260,12 +267,6 @@ static irqreturn_t vt8500_irq(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static unsigned int vt8500_tx_empty(struct uart_port *port)
-{
-	return (vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16 ?
-						TIOCSER_TEMT : 0;
-}
-
 static unsigned int vt8500_get_mctrl(struct uart_port *port)
 {
 	unsigned int usr;
@@ -355,7 +356,7 @@ static void vt8500_shutdown(struct uart_port *port)
 
 static void vt8500_set_termios(struct uart_port *port,
 			       struct ktermios *termios,
-			       struct ktermios *old)
+			       const struct ktermios *old)
 {
 	struct vt8500_port *vt8500_port =
 			container_of(port, struct vt8500_port, uart);
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 9e01fe6c0ab8..2eff7cff57c4 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -2,7 +2,7 @@
 /*
  * Cadence UART driver (found in Xilinx Zynq)
  *
- * 2011 - 2014 (C) Xilinx Inc.
+ * Copyright (c) 2011 - 2014 Xilinx, Inc.
  *
  * This driver has originally been pushed by Xilinx using a Zynq-branding. This
  * still shows in the naming of this file, the kconfig symbols and some symbols
@@ -361,6 +361,8 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
 		isrstatus &= ~CDNS_UART_IXR_TXEMPTY;
 	}
 
+	isrstatus &= port->read_status_mask;
+	isrstatus &= ~port->ignore_status_mask;
 	/*
 	 * Skip RX processing if RX is disabled as RXEMPTY will never be set
 	 * as read bytes will not be removed from the FIFO.
@@ -675,7 +677,8 @@ static void cdns_uart_break_ctl(struct uart_port *port, int ctl)
  * @old: Values of the previously saved termios structure
  */
 static void cdns_uart_set_termios(struct uart_port *port,
-				struct ktermios *termios, struct ktermios *old)
+				  struct ktermios *termios,
+				  const struct ktermios *old)
 {
 	u32 cval = 0;
 	unsigned int baud, minbaud, maxbaud;
@@ -1130,8 +1133,35 @@ static struct uart_driver cdns_uart_uart_driver;
  */
 static void cdns_uart_console_putchar(struct uart_port *port, unsigned char ch)
 {
-	while (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)
+	unsigned int ctrl_reg;
+	unsigned long timeout;
+
+	timeout = jiffies + msecs_to_jiffies(1000);
+	while (1) {
+		ctrl_reg = readl(port->membase + CDNS_UART_CR);
+		if (!(ctrl_reg & CDNS_UART_CR_TX_DIS))
+			break;
+		if (time_after(jiffies, timeout)) {
+			dev_warn(port->dev,
+				 "timeout waiting for Enable\n");
+			return;
+		}
+		cpu_relax();
+	}
+
+	timeout = jiffies + msecs_to_jiffies(1000);
+	while (1) {
+		ctrl_reg = readl(port->membase + CDNS_UART_SR);
+
+		if (!(ctrl_reg & CDNS_UART_SR_TXFULL))
+			break;
+		if (time_after(jiffies, timeout)) {
+			dev_warn(port->dev,
+				 "timeout waiting for TX fifo\n");
+			return;
+		}
 		cpu_relax();
+	}
 	writel(ch, port->membase + CDNS_UART_FIFO);
 }
 
@@ -1329,12 +1359,20 @@ static int cdns_uart_resume(struct device *device)
 	unsigned long flags;
 	u32 ctrl_reg;
 	int may_wake;
+	int ret;
 
 	may_wake = device_may_wakeup(device);
 
 	if (console_suspend_enabled && uart_console(port) && !may_wake) {
-		clk_enable(cdns_uart->pclk);
-		clk_enable(cdns_uart->uartclk);
+		ret = clk_enable(cdns_uart->pclk);
+		if (ret)
+			return ret;
+
+		ret = clk_enable(cdns_uart->uartclk);
+		if (ret) {
+			clk_disable(cdns_uart->pclk);
+			return ret;
+		}
 
 		spin_lock_irqsave(&port->lock, flags);
 
@@ -1383,9 +1421,17 @@ static int __maybe_unused cdns_runtime_resume(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
 	struct cdns_uart *cdns_uart = port->private_data;
+	int ret;
 
-	clk_enable(cdns_uart->pclk);
-	clk_enable(cdns_uart->uartclk);
+	ret = clk_enable(cdns_uart->pclk);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(cdns_uart->uartclk);
+	if (ret) {
+		clk_disable(cdns_uart->pclk);
+		return ret;
+	}
 	return 0;
 };
 
@@ -1551,6 +1597,8 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	port->dev = &pdev->dev;
 	port->uartclk = clk_get_rate(cdns_uart_data->uartclk);
 	port->private_data = cdns_uart_data;
+	port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |
+			CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_TOUT;
 	cdns_uart_data->port = port;
 	platform_set_drvdata(pdev, port);
 
diff --git a/drivers/tty/serial/zs.c b/drivers/tty/serial/zs.c
index 5bc58591665a..688db7d8b748 100644
--- a/drivers/tty/serial/zs.c
+++ b/drivers/tty/serial/zs.c
@@ -846,7 +846,7 @@ static void zs_reset(struct zs_port *zport)
 }
 
 static void zs_set_termios(struct uart_port *uport, struct ktermios *termios,
-			   struct ktermios *old_termios)
+			   const struct ktermios *old_termios)
 {
 	struct zs_port *zport = to_zport(uport);
 	struct zs_scc *scc = zport->scc;
diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c
index 9bc2a9265277..25e9befdda3a 100644
--- a/drivers/tty/synclink_gt.c
+++ b/drivers/tty/synclink_gt.c
@@ -91,7 +91,6 @@ static char *driver_name     = "SyncLink GT";
 static char *slgt_driver_name = "synclink_gt";
 static char *tty_dev_prefix  = "ttySLG";
 MODULE_LICENSE("GPL");
-#define MGSL_MAGIC 0x5401
 #define MAX_DEVICES 32
 
 static const struct pci_device_id pci_table[] = {
@@ -215,8 +214,6 @@ struct slgt_info {
 
 	struct slgt_info *next_device;	/* device list link */
 
-	int magic;
-
 	char device_name[25];
 	struct pci_dev *pdev;
 
@@ -554,10 +551,6 @@ static inline int sanity_check(struct slgt_info *info, char *devname, const char
 		printk("null struct slgt_info for (%s) in %s\n", devname, name);
 		return 1;
 	}
-	if (info->magic != MGSL_MAGIC) {
-		printk("bad magic number struct slgt_info (%s) in %s\n", devname, name);
-		return 1;
-	}
 #else
 	if (!info)
 		return 1;
@@ -707,7 +700,8 @@ static void hangup(struct tty_struct *tty)
 	wake_up_interruptible(&info->port.open_wait);
 }
 
-static void set_termios(struct tty_struct *tty, struct ktermios *old_termios)
+static void set_termios(struct tty_struct *tty,
+			const struct ktermios *old_termios)
 {
 	struct slgt_info *info = tty->driver_data;
 	unsigned long flags;
@@ -3498,7 +3492,6 @@ static struct slgt_info *alloc_dev(int adapter_num, int port_num, struct pci_dev
 	} else {
 		tty_port_init(&info->port);
 		info->port.ops = &slgt_port_ops;
-		info->magic = MGSL_MAGIC;
 		INIT_WORK(&info->task, bh_handler);
 		info->max_frame_size = 4096;
 		info->base_clock = 14745600;
diff --git a/drivers/tty/tty.h b/drivers/tty/tty.h
index f310a8274df1..1c08c9b67b16 100644
--- a/drivers/tty/tty.h
+++ b/drivers/tty/tty.h
@@ -73,7 +73,7 @@ void tty_buffer_set_lock_subclass(struct tty_port *port);
 bool tty_buffer_restart_work(struct tty_port *port);
 bool tty_buffer_cancel_work(struct tty_port *port);
 void tty_buffer_flush_work(struct tty_port *port);
-speed_t tty_termios_input_baud_rate(struct ktermios *termios);
+speed_t tty_termios_input_baud_rate(const struct ktermios *termios);
 void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
 int tty_ldisc_reinit(struct tty_struct *tty, int disc);
 long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
diff --git a/drivers/tty/tty_baudrate.c b/drivers/tty/tty_baudrate.c
index 3cd99ed7c710..f9b49939c27b 100644
--- a/drivers/tty/tty_baudrate.c
+++ b/drivers/tty/tty_baudrate.c
@@ -49,13 +49,13 @@ static int n_baud_table = ARRAY_SIZE(baud_table);
  *
  *	Convert termios baud rate data into a speed. This should be called
  *	with the termios lock held if this termios is a terminal termios
- *	structure. May change the termios data. Device drivers can call this
- *	function but should use ->c_[io]speed directly as they are updated.
+ *	structure. Device drivers can call this function but should use
+ *	->c_[io]speed directly as they are updated.
  *
  *	Locking: none
  */
 
-speed_t tty_termios_baud_rate(struct ktermios *termios)
+speed_t tty_termios_baud_rate(const struct ktermios *termios)
 {
 	unsigned int cbaud;
 
@@ -67,11 +67,7 @@ speed_t tty_termios_baud_rate(struct ktermios *termios)
 
 	if (cbaud & CBAUDEX) {
 		cbaud &= ~CBAUDEX;
-
-		if (cbaud < 1 || cbaud + 15 > n_baud_table)
-			termios->c_cflag &= ~CBAUDEX;
-		else
-			cbaud += 15;
+		cbaud += 15;
 	}
 	return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
 }
@@ -83,30 +79,26 @@ EXPORT_SYMBOL(tty_termios_baud_rate);
  *
  *	Convert termios baud rate data into a speed. This should be called
  *	with the termios lock held if this termios is a terminal termios
- *	structure. May change the termios data. Device drivers can call this
- *	function but should use ->c_[io]speed directly as they are updated.
+ *	structure. Device drivers can call this function but should use
+ *	->c_[io]speed directly as they are updated.
  *
  *	Locking: none
  */
 
-speed_t tty_termios_input_baud_rate(struct ktermios *termios)
+speed_t tty_termios_input_baud_rate(const struct ktermios *termios)
 {
 	unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
 
 	if (cbaud == B0)
 		return tty_termios_baud_rate(termios);
 
-	/* Magic token for arbitrary speed via c_ispeed*/
+	/* Magic token for arbitrary speed via c_ispeed */
 	if (cbaud == BOTHER)
 		return termios->c_ispeed;
 
 	if (cbaud & CBAUDEX) {
 		cbaud &= ~CBAUDEX;
-
-		if (cbaud < 1 || cbaud + 15 > n_baud_table)
-			termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
-		else
-			cbaud += 15;
+		cbaud += 15;
 	}
 	return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
 }
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 82a8855981f7..de06c3c2ff70 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -99,8 +99,8 @@
 #include <linux/serial.h>
 #include <linux/ratelimit.h>
 #include <linux/compat.h>
-
 #include <linux/uaccess.h>
+#include <linux/termios_internal.h>
 
 #include <linux/kbd_kern.h>
 #include <linux/vt_kern.h>
@@ -170,7 +170,6 @@ static void free_tty_struct(struct tty_struct *tty)
 	tty_ldisc_deinit(tty);
 	put_device(tty->dev);
 	kvfree(tty->write_buf);
-	tty->magic = 0xDEADDEAD;
 	kfree(tty);
 }
 
@@ -265,11 +264,6 @@ static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
 			imajor(inode), iminor(inode), routine);
 		return 1;
 	}
-	if (tty->magic != TTY_MAGIC) {
-		pr_warn("(%d:%d): %s: bad magic number\n",
-			imajor(inode), iminor(inode), routine);
-		return 1;
-	}
 #endif
 	return 0;
 }
@@ -1533,7 +1527,6 @@ static void release_one_tty(struct work_struct *work)
 	if (tty->ops->cleanup)
 		tty->ops->cleanup(tty);
 
-	tty->magic = 0;
 	tty_driver_kref_put(driver);
 	module_put(owner);
 
@@ -3093,7 +3086,6 @@ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx)
 		return NULL;
 
 	kref_init(&tty->kref);
-	tty->magic = TTY_MAGIC;
 	if (tty_ldisc_init(tty)) {
 		kfree(tty);
 		return NULL;
@@ -3329,7 +3321,6 @@ struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
 		return ERR_PTR(-ENOMEM);
 
 	kref_init(&driver->kref);
-	driver->magic = TTY_DRIVER_MAGIC;
 	driver->num = lines;
 	driver->owner = owner;
 	driver->flags = flags;
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index 2a76b330e108..ce511557b98b 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -21,6 +21,7 @@
 #include <linux/bitops.h>
 #include <linux/mutex.h>
 #include <linux/compat.h>
+#include <linux/termios_internal.h>
 #include "tty.h"
 
 #include <asm/io.h>
@@ -219,7 +220,7 @@ EXPORT_SYMBOL(tty_wait_until_sent);
  *		Termios Helper Methods
  */
 
-static void unset_locked_termios(struct tty_struct *tty, struct ktermios *old)
+static void unset_locked_termios(struct tty_struct *tty, const struct ktermios *old)
 {
 	struct ktermios *termios = &tty->termios;
 	struct ktermios *locked  = &tty->termios_locked;
@@ -249,7 +250,7 @@ static void unset_locked_termios(struct tty_struct *tty, struct ktermios *old)
  *	in some cases where only minimal reconfiguration is supported
  */
 
-void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
+void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old)
 {
 	/* The bits a dumb device handles in software. Smart devices need
 	   to always provide a set_termios method */
@@ -374,6 +375,80 @@ int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
 }
 EXPORT_SYMBOL_GPL(tty_set_termios);
 
+
+/*
+ * Translate a "termio" structure into a "termios". Ugh.
+ */
+__weak int user_termio_to_kernel_termios(struct ktermios *termios,
+						struct termio __user *termio)
+{
+	struct termio v;
+
+	if (copy_from_user(&v, termio, sizeof(struct termio)))
+		return -EFAULT;
+
+	termios->c_iflag = (0xffff0000 & termios->c_iflag) | v.c_iflag;
+	termios->c_oflag = (0xffff0000 & termios->c_oflag) | v.c_oflag;
+	termios->c_cflag = (0xffff0000 & termios->c_cflag) | v.c_cflag;
+	termios->c_lflag = (0xffff0000 & termios->c_lflag) | v.c_lflag;
+	termios->c_line = (0xffff0000 & termios->c_lflag) | v.c_line;
+	memcpy(termios->c_cc, v.c_cc, NCC);
+	return 0;
+}
+
+/*
+ * Translate a "termios" structure into a "termio". Ugh.
+ */
+__weak int kernel_termios_to_user_termio(struct termio __user *termio,
+						struct ktermios *termios)
+{
+	struct termio v;
+	memset(&v, 0, sizeof(struct termio));
+	v.c_iflag = termios->c_iflag;
+	v.c_oflag = termios->c_oflag;
+	v.c_cflag = termios->c_cflag;
+	v.c_lflag = termios->c_lflag;
+	v.c_line = termios->c_line;
+	memcpy(v.c_cc, termios->c_cc, NCC);
+	return copy_to_user(termio, &v, sizeof(struct termio));
+}
+
+#ifdef TCGETS2
+__weak int user_termios_to_kernel_termios(struct ktermios *k,
+						 struct termios2 __user *u)
+{
+	return copy_from_user(k, u, sizeof(struct termios2));
+}
+__weak int kernel_termios_to_user_termios(struct termios2 __user *u,
+						 struct ktermios *k)
+{
+	return copy_to_user(u, k, sizeof(struct termios2));
+}
+__weak int user_termios_to_kernel_termios_1(struct ktermios *k,
+						   struct termios __user *u)
+{
+	return copy_from_user(k, u, sizeof(struct termios));
+}
+__weak int kernel_termios_to_user_termios_1(struct termios __user *u,
+						   struct ktermios *k)
+{
+	return copy_to_user(u, k, sizeof(struct termios));
+}
+
+#else
+
+__weak int user_termios_to_kernel_termios(struct ktermios *k,
+						 struct termios __user *u)
+{
+	return copy_from_user(k, u, sizeof(struct termios));
+}
+__weak int kernel_termios_to_user_termios(struct termios __user *u,
+						 struct ktermios *k)
+{
+	return copy_to_user(u, k, sizeof(struct termios));
+}
+#endif /* TCGETS2 */
+
 /**
  *	set_termios		-	set termios values for a tty
  *	@tty: terminal device
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
index 393518a24cfe..784e46a0a3b1 100644
--- a/drivers/tty/tty_mutex.c
+++ b/drivers/tty/tty_mutex.c
@@ -14,8 +14,6 @@
 
 void tty_lock(struct tty_struct *tty)
 {
-	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
-		return;
 	tty_kref_get(tty);
 	mutex_lock(&tty->legacy_mutex);
 }
@@ -25,8 +23,6 @@ int tty_lock_interruptible(struct tty_struct *tty)
 {
 	int ret;
 
-	if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty))
-		return -EIO;
 	tty_kref_get(tty);
 	ret = mutex_lock_interruptible(&tty->legacy_mutex);
 	if (ret)
@@ -36,8 +32,6 @@ int tty_lock_interruptible(struct tty_struct *tty)
 
 void tty_unlock(struct tty_struct *tty)
 {
-	if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty))
-		return;
 	mutex_unlock(&tty->legacy_mutex);
 	tty_kref_put(tty);
 }
diff --git a/drivers/tty/vcc.c b/drivers/tty/vcc.c
index e11383ae1e7e..34ba6e54789a 100644
--- a/drivers/tty/vcc.c
+++ b/drivers/tty/vcc.c
@@ -11,6 +11,7 @@
 #include <linux/sysfs.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
+#include <linux/termios_internal.h>
 #include <asm/vio.h>
 #include <asm/ldc.h>
 
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 0b669c82ddc9..981d2bfcf9a5 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -154,10 +154,10 @@ static void console_callback(struct work_struct *ignored);
 static void con_driver_unregister_callback(struct work_struct *ignored);
 static void blank_screen_t(struct timer_list *unused);
 static void set_palette(struct vc_data *vc);
+static void unblank_screen(void);
 
 #define vt_get_kmsg_redirect() vt_kmsg_redirect(-1)
 
-static int printable;		/* Is console ready for printing? */
 int default_utf8 = true;
 module_param(default_utf8, int, S_IRUGO | S_IWUSR);
 int global_cursor_default = -1;
@@ -3084,9 +3084,9 @@ static void vt_console_print(struct console *co, const char *b, unsigned count)
 	ushort start_x, cnt;
 	int kmsg_console;
 
-	/* console busy or not yet initialized */
-	if (!printable)
-		return;
+	WARN_CONSOLE_UNLOCKED();
+
+	/* this protects against concurrent oops only */
 	if (!spin_trylock(&printing_lock))
 		return;
 
@@ -3537,7 +3537,6 @@ static int __init con_init(void)
 	pr_info("Console: %s %s %dx%d\n",
 		vc->vc_can_do_color ? "colour" : "mono",
 		display_desc, vc->vc_cols, vc->vc_rows);
-	printable = 1;
 
 	console_unlock();
 
@@ -4452,7 +4451,7 @@ EXPORT_SYMBOL(do_unblank_screen);
  * call it with 1 as an argument and so force a mode restore... that may kill
  * X or at least garbage the screen but would also make the Oops visible...
  */
-void unblank_screen(void)
+static void unblank_screen(void)
 {
 	do_unblank_screen(0);
 }
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index cc637c4599e1..36bf051b345b 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -51,7 +51,7 @@ static DEFINE_IDR(acm_minors);
 static DEFINE_MUTEX(acm_minors_lock);
 
 static void acm_tty_set_termios(struct tty_struct *tty,
-				struct ktermios *termios_old);
+				const struct ktermios *termios_old);
 
 /*
  * acm_minors accessors
@@ -1049,7 +1049,7 @@ static int acm_tty_ioctl(struct tty_struct *tty,
 }
 
 static void acm_tty_set_termios(struct tty_struct *tty,
-						struct ktermios *termios_old)
+				const struct ktermios *termios_old)
 {
 	struct acm *acm = tty->driver_data;
 	struct ktermios *termios = &tty->termios;
diff --git a/drivers/usb/serial/ark3116.c b/drivers/usb/serial/ark3116.c
index 39eaa7b97c40..9452291f1703 100644
--- a/drivers/usb/serial/ark3116.c
+++ b/drivers/usb/serial/ark3116.c
@@ -189,7 +189,7 @@ static void ark3116_port_remove(struct usb_serial_port *port)
 
 static void ark3116_set_termios(struct tty_struct *tty,
 				struct usb_serial_port *port,
-				struct ktermios *old_termios)
+				const struct ktermios *old_termios)
 {
 	struct usb_serial *serial = port->serial;
 	struct ark3116_private *priv = usb_get_serial_port_data(port);
diff --git a/drivers/usb/serial/belkin_sa.c b/drivers/usb/serial/belkin_sa.c
index 8107e4b5b03b..9331a562dac0 100644
--- a/drivers/usb/serial/belkin_sa.c
+++ b/drivers/usb/serial/belkin_sa.c
@@ -44,7 +44,8 @@ static void belkin_sa_close(struct usb_serial_port *port);
 static void belkin_sa_read_int_callback(struct urb *urb);
 static void belkin_sa_process_read_urb(struct urb *urb);
 static void belkin_sa_set_termios(struct tty_struct *tty,
-			struct usb_serial_port *port, struct ktermios * old);
+				  struct usb_serial_port *port,
+				  const struct ktermios *old_termios);
 static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state);
 static int  belkin_sa_tiocmget(struct tty_struct *tty);
 static int  belkin_sa_tiocmset(struct tty_struct *tty,
@@ -273,7 +274,8 @@ static void belkin_sa_process_read_urb(struct urb *urb)
 }
 
 static void belkin_sa_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				  struct usb_serial_port *port,
+				  const struct ktermios *old_termios)
 {
 	struct usb_serial *serial = port->serial;
 	struct belkin_sa_private *priv = usb_get_serial_port_data(port);
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index af01a462cc43..6e1b87e67304 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -106,7 +106,7 @@ struct ch341_private {
 
 static void ch341_set_termios(struct tty_struct *tty,
 			      struct usb_serial_port *port,
-			      struct ktermios *old_termios);
+			      const struct ktermios *old_termios);
 
 static int ch341_control_out(struct usb_device *dev, u8 request,
 			     u16 value, u16 index)
@@ -482,7 +482,8 @@ err_kill_interrupt_urb:
  * tty->termios contains the new setting to be used.
  */
 static void ch341_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+			      struct usb_serial_port *port,
+			      const struct ktermios *old_termios)
 {
 	struct ch341_private *priv = usb_get_serial_port_data(port);
 	unsigned baud_rate;
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index a34957c4b64c..3bcec419f463 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -31,9 +31,9 @@
 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
 static void cp210x_close(struct usb_serial_port *);
 static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
-							struct ktermios *);
+				const struct ktermios *);
 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
-							struct ktermios*);
+			       const struct ktermios *);
 static bool cp210x_tx_empty(struct usb_serial_port *port);
 static int cp210x_tiocmget(struct tty_struct *);
 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
@@ -1040,7 +1040,8 @@ static speed_t cp210x_get_actual_rate(speed_t baud)
  * otherwise.
  */
 static void cp210x_change_speed(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
 {
 	struct usb_serial *serial = port->serial;
 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
@@ -1122,7 +1123,8 @@ static bool cp210x_termios_change(const struct ktermios *a, const struct ktermio
 }
 
 static void cp210x_set_flow_control(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				    struct usb_serial_port *port,
+				    const struct ktermios *old_termios)
 {
 	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
@@ -1232,7 +1234,8 @@ out_unlock:
 }
 
 static void cp210x_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+		               struct usb_serial_port *port,
+		               const struct ktermios *old_termios)
 {
 	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
 	u16 bits;
diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index 5fbcc155e8f5..1e0c028c5ec9 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -125,7 +125,8 @@ static void cypress_send(struct usb_serial_port *port);
 static unsigned int cypress_write_room(struct tty_struct *tty);
 static void cypress_earthmate_init_termios(struct tty_struct *tty);
 static void cypress_set_termios(struct tty_struct *tty,
-			struct usb_serial_port *port, struct ktermios *old);
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios);
 static int  cypress_tiocmget(struct tty_struct *tty);
 static int  cypress_tiocmset(struct tty_struct *tty,
 			unsigned int set, unsigned int clear);
@@ -859,7 +860,8 @@ static void cypress_earthmate_init_termios(struct tty_struct *tty)
 }
 
 static void cypress_set_termios(struct tty_struct *tty,
-	struct usb_serial_port *port, struct ktermios *old_termios)
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
 {
 	struct cypress_private *priv = usb_get_serial_port_data(port);
 	struct device *dev = &port->dev;
diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index af65eb863d70..45d688e9b93f 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -215,7 +215,8 @@ static int digi_transmit_idle(struct usb_serial_port *port,
 static void digi_rx_throttle(struct tty_struct *tty);
 static void digi_rx_unthrottle(struct tty_struct *tty);
 static void digi_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios);
+			     struct usb_serial_port *port,
+			     const struct ktermios *old_termios);
 static void digi_break_ctl(struct tty_struct *tty, int break_state);
 static int digi_tiocmget(struct tty_struct *tty);
 static int digi_tiocmset(struct tty_struct *tty, unsigned int set,
@@ -649,7 +650,8 @@ static void digi_rx_unthrottle(struct tty_struct *tty)
 
 
 static void digi_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+			     struct usb_serial_port *port,
+			     const struct ktermios *old_termios)
 {
 	struct digi_port *priv = usb_get_serial_port_data(port);
 	struct device *dev = &port->dev;
diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index d9f20256a6a8..2dd58cd9f0cc 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -603,7 +603,8 @@ static int f81232_port_disable(struct usb_serial_port *port)
 }
 
 static void f81232_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+			       struct usb_serial_port *port,
+			       const struct ktermios *old_termios)
 {
 	struct f81232_private *priv = usb_get_serial_port_data(port);
 	u8 new_lcr = 0;
diff --git a/drivers/usb/serial/f81534.c b/drivers/usb/serial/f81534.c
index d789c1ec87b3..ddfcd72eb0ae 100644
--- a/drivers/usb/serial/f81534.c
+++ b/drivers/usb/serial/f81534.c
@@ -944,8 +944,8 @@ static int f81534_calc_num_ports(struct usb_serial *serial,
 }
 
 static void f81534_set_termios(struct tty_struct *tty,
-				struct usb_serial_port *port,
-				struct ktermios *old_termios)
+			       struct usb_serial_port *port,
+			       const struct ktermios *old_termios)
 {
 	u8 new_lcr = 0;
 	int status;
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 52d59be92034..0a1da579ead5 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1089,7 +1089,8 @@ static void ftdi_process_read_urb(struct urb *urb);
 static int ftdi_prepare_write_buffer(struct usb_serial_port *port,
 						void *dest, size_t size);
 static void ftdi_set_termios(struct tty_struct *tty,
-			struct usb_serial_port *port, struct ktermios *old);
+			     struct usb_serial_port *port,
+			     const struct ktermios *old_termios);
 static int  ftdi_tiocmget(struct tty_struct *tty);
 static int  ftdi_tiocmset(struct tty_struct *tty,
 			unsigned int set, unsigned int clear);
@@ -2640,7 +2641,8 @@ static bool ftdi_tx_empty(struct usb_serial_port *port)
  * WARNING: set_termios calls this with old_termios in kernel space
  */
 static void ftdi_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+		             struct usb_serial_port *port,
+		             const struct ktermios *old_termios)
 {
 	struct usb_device *dev = port->serial->dev;
 	struct device *ddev = &port->dev;
diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c
index ffa622539a25..3a4c0febf335 100644
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -281,7 +281,7 @@ static int  send_iosp_ext_cmd(struct edgeport_port *edge_port, __u8 command,
 static int  calc_baud_rate_divisor(struct device *dev, int baud_rate, int *divisor);
 static void change_port_settings(struct tty_struct *tty,
 				struct edgeport_port *edge_port,
-				struct ktermios *old_termios);
+				const struct ktermios *old_termios);
 static int  send_cmd_write_uart_register(struct edgeport_port *edge_port,
 				__u8 regNum, __u8 regValue);
 static int  write_cmd_usb(struct edgeport_port *edge_port,
@@ -1441,7 +1441,8 @@ static void edge_unthrottle(struct tty_struct *tty)
  * the termios structure
  *****************************************************************************/
 static void edge_set_termios(struct tty_struct *tty,
-	struct usb_serial_port *port, struct ktermios *old_termios)
+			     struct usb_serial_port *port,
+			     const struct ktermios *old_termios)
 {
 	struct edgeport_port *edge_port = usb_get_serial_port_data(port);
 
@@ -2325,7 +2326,7 @@ static int send_cmd_write_uart_register(struct edgeport_port *edge_port,
  *****************************************************************************/
 
 static void change_port_settings(struct tty_struct *tty,
-	struct edgeport_port *edge_port, struct ktermios *old_termios)
+	struct edgeport_port *edge_port, const struct ktermios *old_termios)
 {
 	struct device *dev = &edge_port->port->dev;
 	struct edgeport_serial *edge_serial =
diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index feba2a8d1233..bc3c24ea42c1 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -221,7 +221,8 @@ static void stop_read(struct edgeport_port *edge_port);
 static int restart_read(struct edgeport_port *edge_port);
 
 static void edge_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios);
+			     struct usb_serial_port *port,
+			     const struct ktermios *old_termios);
 static void edge_send(struct usb_serial_port *port, struct tty_struct *tty);
 
 static int do_download_mode(struct edgeport_serial *serial,
@@ -2210,7 +2211,7 @@ static int restart_read(struct edgeport_port *edge_port)
 }
 
 static void change_port_settings(struct tty_struct *tty,
-		struct edgeport_port *edge_port, struct ktermios *old_termios)
+		struct edgeport_port *edge_port, const struct ktermios *old_termios)
 {
 	struct device *dev = &edge_port->port->dev;
 	struct ump_uart_config *config;
@@ -2351,7 +2352,8 @@ static void change_port_settings(struct tty_struct *tty,
 }
 
 static void edge_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+			     struct usb_serial_port *port,
+			     const struct ktermios *old_termios)
 {
 	struct edgeport_port *edge_port = usb_get_serial_port_data(port);
 
diff --git a/drivers/usb/serial/ir-usb.c b/drivers/usb/serial/ir-usb.c
index 7b44dbea95cd..82f108134e6f 100644
--- a/drivers/usb/serial/ir-usb.c
+++ b/drivers/usb/serial/ir-usb.c
@@ -51,7 +51,8 @@ static unsigned int ir_write_room(struct tty_struct *tty);
 static void ir_write_bulk_callback(struct urb *urb);
 static void ir_process_read_urb(struct urb *urb);
 static void ir_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios);
+			   struct usb_serial_port *port,
+			   const struct ktermios *old_termios);
 
 /* Not that this lot means you can only have one per system */
 static u8 ir_baud;
@@ -376,7 +377,8 @@ static void ir_process_read_urb(struct urb *urb)
 }
 
 static void ir_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+			   struct usb_serial_port *port,
+			   const struct ktermios *old_termios)
 {
 	struct usb_device *udev = port->serial->dev;
 	unsigned char *transfer_buffer;
diff --git a/drivers/usb/serial/iuu_phoenix.c b/drivers/usb/serial/iuu_phoenix.c
index 0be3b5e1eaf3..77cba71bcccb 100644
--- a/drivers/usb/serial/iuu_phoenix.c
+++ b/drivers/usb/serial/iuu_phoenix.c
@@ -879,7 +879,8 @@ static int iuu_uart_baud(struct usb_serial_port *port, u32 baud_base,
 }
 
 static void iuu_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+			    struct usb_serial_port *port,
+			    const struct ktermios *old_termios)
 {
 	const u32 supported_mask = CMSPAR|PARENB|PARODD;
 	struct iuu_private *priv = usb_get_serial_port_data(port);
diff --git a/drivers/usb/serial/keyspan.c b/drivers/usb/serial/keyspan.c
index 1cfcd805f286..2966e0c4941e 100644
--- a/drivers/usb/serial/keyspan.c
+++ b/drivers/usb/serial/keyspan.c
@@ -616,7 +616,8 @@ static void keyspan_break_ctl(struct tty_struct *tty, int break_state)
 
 
 static void keyspan_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
 {
 	int				baud_rate, device_port;
 	struct keyspan_port_private 	*p_priv;
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 3e7628becdcd..6fd15cd9e1eb 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -321,7 +321,8 @@ static void keyspan_pda_break_ctl(struct tty_struct *tty, int break_state)
 }
 
 static void keyspan_pda_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				    struct usb_serial_port *port,
+				    const struct ktermios *old_termios)
 {
 	struct usb_serial *serial = port->serial;
 	speed_t speed;
diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index edcc57bd9b5e..394b3189e003 100644
--- a/drivers/usb/serial/kl5kusb105.c
+++ b/drivers/usb/serial/kl5kusb105.c
@@ -56,7 +56,8 @@ static void klsi_105_port_remove(struct usb_serial_port *port);
 static int  klsi_105_open(struct tty_struct *tty, struct usb_serial_port *port);
 static void klsi_105_close(struct usb_serial_port *port);
 static void klsi_105_set_termios(struct tty_struct *tty,
-			struct usb_serial_port *port, struct ktermios *old);
+				 struct usb_serial_port *port,
+				 const struct ktermios *old_termios);
 static int  klsi_105_tiocmget(struct tty_struct *tty);
 static void klsi_105_process_read_urb(struct urb *urb);
 static int klsi_105_prepare_write_buffer(struct usb_serial_port *port,
@@ -366,7 +367,7 @@ static void klsi_105_process_read_urb(struct urb *urb)
 
 static void klsi_105_set_termios(struct tty_struct *tty,
 				 struct usb_serial_port *port,
-				 struct ktermios *old_termios)
+				 const struct ktermios *old_termios)
 {
 	struct klsi_105_private *priv = usb_get_serial_port_data(port);
 	struct device *dev = &port->dev;
diff --git a/drivers/usb/serial/kobil_sct.c b/drivers/usb/serial/kobil_sct.c
index 4ed8b8b0a361..5e775f68fcb8 100644
--- a/drivers/usb/serial/kobil_sct.c
+++ b/drivers/usb/serial/kobil_sct.c
@@ -62,7 +62,8 @@ static int  kobil_tiocmset(struct tty_struct *tty,
 static void kobil_read_int_callback(struct urb *urb);
 static void kobil_write_int_callback(struct urb *urb);
 static void kobil_set_termios(struct tty_struct *tty,
-			struct usb_serial_port *port, struct ktermios *old);
+			      struct usb_serial_port *port,
+			      const struct ktermios *old);
 static void kobil_init_termios(struct tty_struct *tty);
 
 static const struct usb_device_id id_table[] = {
@@ -474,7 +475,8 @@ static int kobil_tiocmset(struct tty_struct *tty,
 }
 
 static void kobil_set_termios(struct tty_struct *tty,
-			struct usb_serial_port *port, struct ktermios *old)
+			      struct usb_serial_port *port,
+			      const struct ktermios *old)
 {
 	struct kobil_private *priv;
 	int result;
diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index ecd5b921e374..d3852feb81a4 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -45,7 +45,8 @@ static void mct_u232_close(struct usb_serial_port *port);
 static void mct_u232_dtr_rts(struct usb_serial_port *port, int on);
 static void mct_u232_read_int_callback(struct urb *urb);
 static void mct_u232_set_termios(struct tty_struct *tty,
-			struct usb_serial_port *port, struct ktermios *old);
+				 struct usb_serial_port *port,
+				 const struct ktermios *old_termios);
 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state);
 static int  mct_u232_tiocmget(struct tty_struct *tty);
 static int  mct_u232_tiocmset(struct tty_struct *tty,
@@ -593,7 +594,7 @@ exit:
 
 static void mct_u232_set_termios(struct tty_struct *tty,
 				 struct usb_serial_port *port,
-				 struct ktermios *old_termios)
+				 const struct ktermios *old_termios)
 {
 	struct usb_serial *serial = port->serial;
 	struct mct_u232_private *priv = usb_get_serial_port_data(port);
diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index 23ccbba716c7..1d1f85fabc28 100644
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -1356,7 +1356,7 @@ static int send_cmd_write_baud_rate(struct moschip_port *mos7720_port,
  */
 static void change_port_settings(struct tty_struct *tty,
 				 struct moschip_port *mos7720_port,
-				 struct ktermios *old_termios)
+				 const struct ktermios *old_termios)
 {
 	struct usb_serial_port *port;
 	struct usb_serial *serial;
@@ -1494,7 +1494,8 @@ static void change_port_settings(struct tty_struct *tty,
  *	termios structure.
  */
 static void mos7720_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
 {
 	int status;
 	struct moschip_port *mos7720_port;
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 925067a7978d..6b12bb4648b8 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -1188,7 +1188,8 @@ static int mos7840_send_cmd_write_baud_rate(struct moschip_port *mos7840_port,
  *****************************************************************************/
 
 static void mos7840_change_port_settings(struct tty_struct *tty,
-	struct moschip_port *mos7840_port, struct ktermios *old_termios)
+					 struct moschip_port *mos7840_port,
+					 const struct ktermios *old_termios)
 {
 	struct usb_serial_port *port = mos7840_port->port;
 	int baud;
@@ -1330,7 +1331,7 @@ static void mos7840_change_port_settings(struct tty_struct *tty,
 
 static void mos7840_set_termios(struct tty_struct *tty,
 				struct usb_serial_port *port,
-				struct ktermios *old_termios)
+				const struct ktermios *old_termios)
 {
 	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
 	int status;
diff --git a/drivers/usb/serial/mxuport.c b/drivers/usb/serial/mxuport.c
index eb45a9b0005c..faa0eedfe245 100644
--- a/drivers/usb/serial/mxuport.c
+++ b/drivers/usb/serial/mxuport.c
@@ -760,7 +760,7 @@ static int mxuport_tiocmget(struct tty_struct *tty)
 }
 
 static int mxuport_set_termios_flow(struct tty_struct *tty,
-				    struct ktermios *old_termios,
+				    const struct ktermios *old_termios,
 				    struct usb_serial_port *port,
 				    struct usb_serial *serial)
 {
@@ -834,7 +834,7 @@ out:
 
 static void mxuport_set_termios(struct tty_struct *tty,
 				struct usb_serial_port *port,
-				struct ktermios *old_termios)
+				const struct ktermios *old_termios)
 {
 	struct usb_serial *serial = port->serial;
 	u8 *buf;
diff --git a/drivers/usb/serial/oti6858.c b/drivers/usb/serial/oti6858.c
index a5caedbe72e2..6365cfe5402c 100644
--- a/drivers/usb/serial/oti6858.c
+++ b/drivers/usb/serial/oti6858.c
@@ -119,7 +119,8 @@ struct oti6858_control_pkt {
 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
 static void oti6858_close(struct usb_serial_port *port);
 static void oti6858_set_termios(struct tty_struct *tty,
-			struct usb_serial_port *port, struct ktermios *old);
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios);
 static void oti6858_init_termios(struct tty_struct *tty);
 static void oti6858_read_int_callback(struct urb *urb);
 static void oti6858_read_bulk_callback(struct urb *urb);
@@ -395,7 +396,8 @@ static void oti6858_init_termios(struct tty_struct *tty)
 }
 
 static void oti6858_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
 {
 	struct oti6858_private *priv = usb_get_serial_port_data(port);
 	unsigned long flags;
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 40b1ab3d284d..8949c1891164 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -789,7 +789,8 @@ static bool pl2303_enable_xonxoff(struct tty_struct *tty, const struct pl2303_ty
 }
 
 static void pl2303_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+			       struct usb_serial_port *port,
+			       const struct ktermios *old_termios)
 {
 	struct usb_serial *serial = port->serial;
 	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c
index 36b1e064e51f..6fca40ace83a 100644
--- a/drivers/usb/serial/quatech2.c
+++ b/drivers/usb/serial/quatech2.c
@@ -261,8 +261,8 @@ static int qt2_calc_num_ports(struct usb_serial *serial,
 }
 
 static void qt2_set_termios(struct tty_struct *tty,
-			    struct usb_serial_port *port,
-			    struct ktermios *old_termios)
+		            struct usb_serial_port *port,
+		            const struct ktermios *old_termios)
 {
 	struct usb_device *dev = port->serial->dev;
 	struct qt2_port_private *port_priv;
diff --git a/drivers/usb/serial/spcp8x5.c b/drivers/usb/serial/spcp8x5.c
index 7039dc918827..09a972a838ee 100644
--- a/drivers/usb/serial/spcp8x5.c
+++ b/drivers/usb/serial/spcp8x5.c
@@ -283,7 +283,8 @@ static void spcp8x5_init_termios(struct tty_struct *tty)
 }
 
 static void spcp8x5_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				struct usb_serial_port *port,
+				const struct ktermios *old_termios)
 {
 	struct usb_serial *serial = port->serial;
 	struct spcp8x5_private *priv = usb_get_serial_port_data(port);
diff --git a/drivers/usb/serial/ssu100.c b/drivers/usb/serial/ssu100.c
index 181e302136a5..1e1888b66305 100644
--- a/drivers/usb/serial/ssu100.c
+++ b/drivers/usb/serial/ssu100.c
@@ -214,8 +214,8 @@ out:	kfree(data);
 
 
 static void ssu100_set_termios(struct tty_struct *tty,
-			       struct usb_serial_port *port,
-			       struct ktermios *old_termios)
+		               struct usb_serial_port *port,
+		               const struct ktermios *old_termios)
 {
 	struct usb_device *dev = port->serial->dev;
 	struct ktermios *termios = &tty->termios;
diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index 18c0bd853392..b99f78224846 100644
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -314,7 +314,8 @@ static bool ti_tx_empty(struct usb_serial_port *port);
 static void ti_throttle(struct tty_struct *tty);
 static void ti_unthrottle(struct tty_struct *tty);
 static void ti_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios);
+			   struct usb_serial_port *port,
+			   const struct ktermios *old_termios);
 static int ti_tiocmget(struct tty_struct *tty);
 static int ti_tiocmset(struct tty_struct *tty,
 		unsigned int set, unsigned int clear);
@@ -892,7 +893,8 @@ static void ti_unthrottle(struct tty_struct *tty)
 }
 
 static void ti_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+			   struct usb_serial_port *port,
+			   const struct ktermios *old_termios)
 {
 	struct ti_port *tport = usb_get_serial_port_data(port);
 	struct ti_uart_config *config;
diff --git a/drivers/usb/serial/upd78f0730.c b/drivers/usb/serial/upd78f0730.c
index 63d4a784ae45..c47439bd90fa 100644
--- a/drivers/usb/serial/upd78f0730.c
+++ b/drivers/usb/serial/upd78f0730.c
@@ -296,8 +296,8 @@ static speed_t upd78f0730_get_baud_rate(struct tty_struct *tty)
 }
 
 static void upd78f0730_set_termios(struct tty_struct *tty,
-				struct usb_serial_port *port,
-				struct ktermios *old_termios)
+				   struct usb_serial_port *port,
+				   const struct ktermios *old_termios)
 {
 	struct device *dev = &port->dev;
 	struct upd78f0730_line_control request;
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index e35bea2235c1..164521ee10c6 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -519,7 +519,8 @@ static int serial_ioctl(struct tty_struct *tty,
 	return retval;
 }
 
-static void serial_set_termios(struct tty_struct *tty, struct ktermios *old)
+static void serial_set_termios(struct tty_struct *tty,
+		               const struct ktermios *old)
 {
 	struct usb_serial_port *port = tty->driver_data;
 
diff --git a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
index 332fb92ae575..7f82d40753ee 100644
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -82,7 +82,8 @@ static void whiteheat_close(struct usb_serial_port *port);
 static void whiteheat_get_serial(struct tty_struct *tty,
 			struct serial_struct *ss);
 static void whiteheat_set_termios(struct tty_struct *tty,
-			struct usb_serial_port *port, struct ktermios *old);
+				  struct usb_serial_port *port,
+				  const struct ktermios *old_termios);
 static int  whiteheat_tiocmget(struct tty_struct *tty);
 static int  whiteheat_tiocmset(struct tty_struct *tty,
 			unsigned int set, unsigned int clear);
@@ -442,7 +443,8 @@ static void whiteheat_get_serial(struct tty_struct *tty, struct serial_struct *s
 
 
 static void whiteheat_set_termios(struct tty_struct *tty,
-	struct usb_serial_port *port, struct ktermios *old_termios)
+				  struct usb_serial_port *port,
+				  const struct ktermios *old_termios)
 {
 	firm_setup_port(tty);
 }
diff --git a/drivers/usb/serial/xr_serial.c b/drivers/usb/serial/xr_serial.c
index 6853cd56d8dc..f3811e060a44 100644
--- a/drivers/usb/serial/xr_serial.c
+++ b/drivers/usb/serial/xr_serial.c
@@ -104,7 +104,8 @@ static int xr21v141x_uart_enable(struct usb_serial_port *port);
 static int xr21v141x_uart_disable(struct usb_serial_port *port);
 static int xr21v141x_fifo_reset(struct usb_serial_port *port);
 static void xr21v141x_set_line_settings(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios);
+					struct usb_serial_port *port,
+					const struct ktermios *old_termios);
 
 struct xr_type {
 	int reg_width;
@@ -133,8 +134,8 @@ struct xr_type {
 	int (*disable)(struct usb_serial_port *port);
 	int (*fifo_reset)(struct usb_serial_port *port);
 	void (*set_line_settings)(struct tty_struct *tty,
-			struct usb_serial_port *port,
-			struct ktermios *old_termios);
+				  struct usb_serial_port *port,
+				  const struct ktermios *old_termios);
 };
 
 enum xr_type_id {
@@ -622,8 +623,8 @@ static int xr21v141x_set_baudrate(struct tty_struct *tty, struct usb_serial_port
 }
 
 static void xr_set_flow_mode(struct tty_struct *tty,
-			     struct usb_serial_port *port,
-			     struct ktermios *old_termios)
+		             struct usb_serial_port *port,
+		             const struct ktermios *old_termios)
 {
 	struct xr_data *data = usb_get_serial_port_data(port);
 	const struct xr_type *type = data->type;
@@ -674,7 +675,8 @@ static void xr_set_flow_mode(struct tty_struct *tty,
 }
 
 static void xr21v141x_set_line_settings(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				        struct usb_serial_port *port,
+				        const struct ktermios *old_termios)
 {
 	struct ktermios *termios = &tty->termios;
 	u8 bits = 0;
@@ -732,7 +734,8 @@ static void xr21v141x_set_line_settings(struct tty_struct *tty,
 }
 
 static void xr_cdc_set_line_coding(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+				   struct usb_serial_port *port,
+				   const struct ktermios *old_termios)
 {
 	struct xr_data *data = usb_get_serial_port_data(port);
 	struct usb_host_interface *alt = port->serial->interface->cur_altsetting;
@@ -809,7 +812,8 @@ static void xr_cdc_set_line_coding(struct tty_struct *tty,
 }
 
 static void xr_set_termios(struct tty_struct *tty,
-		struct usb_serial_port *port, struct ktermios *old_termios)
+			   struct usb_serial_port *port,
+			   const struct ktermios *old_termios)
 {
 	struct xr_data *data = usb_get_serial_port_data(port);