Merge tag 'tty-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty and serial driver updates from Greg KH:
 "Here is the big set of tty and serial driver updates for 5.13-rc1.

  Actually busy this release, with a number of cleanups happening:

   - much needed core tty cleanups by Jiri Slaby

   - removal of unused and orphaned old-style serial drivers. If anyone
     shows up with this hardware, it is trivial to restore these but we
     really do not think they are in use anymore.

   - fixes and cleanups from Johan Hovold on a number of termios setting
     corner cases that loads of drivers got wrong as well as removing
     unneeded code due to tty core changes from long ago that were never
     propagated out to the drivers

   - loads of platform-specific serial port driver updates and fixes

   - coding style cleanups and other small fixes and updates all over
     the tty/serial tree.

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

* tag 'tty-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits)
  serial: extend compile-test coverage
  serial: stm32: add FIFO threshold configuration
  dt-bindings: serial: 8250: update TX FIFO trigger level
  dt-bindings: serial: stm32: override FIFO threshold properties
  dt-bindings: serial: add RX and TX FIFO properties
  serial: xilinx_uartps: drop low-latency workaround
  serial: vt8500: drop low-latency workaround
  serial: timbuart: drop low-latency workaround
  serial: sunsu: drop low-latency workaround
  serial: sifive: drop low-latency workaround
  serial: txx9: drop low-latency workaround
  serial: sa1100: drop low-latency workaround
  serial: rp2: drop low-latency workaround
  serial: rda: drop low-latency workaround
  serial: owl: drop low-latency workaround
  serial: msm_serial: drop low-latency workaround
  serial: mpc52xx_uart: drop low-latency workaround
  serial: meson: drop low-latency workaround
  serial: mcf: drop low-latency workaround
  serial: lpc32xx_hs: drop low-latency workaround
  ...

1 files changed, 21 insertions, 16 deletions

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 51dafc06f541..5fea02cfb0cc 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -50,6 +50,7 @@
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/gsmmux.h>
+#include "tty.h"
 
 static int debug;
 module_param(debug, int, 0600);
@@ -266,7 +267,7 @@ struct gsm_mux {
 
 #define MAX_MUX		4			/* 256 minors */
 static struct gsm_mux *gsm_mux[MAX_MUX];	/* GSM muxes */
-static spinlock_t gsm_mux_lock;
+static DEFINE_SPINLOCK(gsm_mux_lock);
 
 static struct tty_driver *gsm_tty_driver;
 
@@ -2384,8 +2385,18 @@ static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
 		/* Don't register device 0 - this is the control channel and not
 		   a usable tty interface */
 		base = mux_num_to_base(gsm); /* Base for this MUX */
-		for (i = 1; i < NUM_DLCI; i++)
-			tty_register_device(gsm_tty_driver, base + i, NULL);
+		for (i = 1; i < NUM_DLCI; i++) {
+			struct device *dev;
+
+			dev = tty_register_device(gsm_tty_driver,
+							base + i, NULL);
+			if (IS_ERR(dev)) {
+				for (i--; i >= 1; i--)
+					tty_unregister_device(gsm_tty_driver,
+								base + i);
+				return PTR_ERR(dev);
+			}
+		}
 	}
 	return ret;
 }
@@ -2416,27 +2427,24 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 			      char *fp, int count)
 {
 	struct gsm_mux *gsm = tty->disc_data;
-	const unsigned char *dp;
-	char *f;
-	int i;
 	char flags = TTY_NORMAL;
 
 	if (debug & 4)
 		print_hex_dump_bytes("gsmld_receive: ", DUMP_PREFIX_OFFSET,
 				     cp, count);
 
-	for (i = count, dp = cp, f = fp; i; i--, dp++) {
-		if (f)
-			flags = *f++;
+	for (; count; count--, cp++) {
+		if (fp)
+			flags = *fp++;
 		switch (flags) {
 		case TTY_NORMAL:
-			gsm->receive(gsm, *dp);
+			gsm->receive(gsm, *cp);
 			break;
 		case TTY_OVERRUN:
 		case TTY_BREAK:
 		case TTY_PARITY:
 		case TTY_FRAME:
-			gsm_error(gsm, *dp, flags);
+			gsm_error(gsm, *cp, flags);
 			break;
 		default:
 			WARN_ONCE(1, "%s: unknown flag %d\n",
@@ -2849,7 +2857,6 @@ static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc)
 /* Line discipline for real tty */
 static struct tty_ldisc_ops tty_ldisc_packet = {
 	.owner		 = THIS_MODULE,
-	.magic           = TTY_LDISC_MAGIC,
 	.name            = "n_gsm",
 	.open            = gsmld_open,
 	.close           = gsmld_close,
@@ -3052,7 +3059,7 @@ static int gsmtty_write_room(struct tty_struct *tty)
 {
 	struct gsm_dlci *dlci = tty->driver_data;
 	if (dlci->state == DLCI_CLOSED)
-		return -EINVAL;
+		return 0;
 	return TX_SIZE - kfifo_len(&dlci->fifo);
 }
 
@@ -3060,7 +3067,7 @@ static int gsmtty_chars_in_buffer(struct tty_struct *tty)
 {
 	struct gsm_dlci *dlci = tty->driver_data;
 	if (dlci->state == DLCI_CLOSED)
-		return -EINVAL;
+		return 0;
 	return kfifo_len(&dlci->fifo);
 }
 
@@ -3261,8 +3268,6 @@ static int __init gsm_init(void)
 	gsm_tty_driver->init_termios.c_lflag &= ~ECHO;
 	tty_set_operations(gsm_tty_driver, &gsmtty_ops);
 
-	spin_lock_init(&gsm_mux_lock);
-
 	if (tty_register_driver(gsm_tty_driver)) {
 		put_tty_driver(gsm_tty_driver);
 		tty_unregister_ldisc(N_GSM0710);