pm24.git/include/linux/serial_8250.h, branch v5.2-rc2

serial: 8250: Rate limit serial port rx interrupts during input overruns

2018-12-17T15:02:57Z

When a serial port gets faulty or gets flooded with inputs, its interrupt handler starts to work double time to get the characters to the workqueue for the tty layer to handle them. When this busy time on the serial/tty subsystem happens during boot, where it is also busy on the userspace trying to initialise, some processes can continuously get preempted and will be on hold until the interrupts subside. The fix is to backoff on processing received characters for a specified amount of time when an input overrun is seen (received a new character before the previous one is processed). This only stops receive and will continue to transmit characters to serial port. After the backoff period is done, it receive will be re-enabled. This is optional and will only be enabled by setting 'overrun-throttle-ms' in the dts. Signed-off-by: Darwin Dingel Signed-off-by: Greg Kroah-Hartman

serial: 8250: export serial8250_do_set_divisor()

2018-07-12T15:07:26Z

Some drivers could call serial8250_do_set_divisor() to complete its own set_divisor routine. Export this symbol for code reusing. Signed-off-by: Jisheng Zhang Reviewed-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman

serial/8250: export serial8250_read_char

2018-04-23T08:16:50Z

Currently, we export serial8250_rx_chars, which does a whole bunch of reads from the 8250 data register, without any form of flow control between reads. An upcoming change to the aspeed vuart driver implements more fine-grained flow control in the interrupt handler, requiring character-at-a-time control over the rx path. This change exports serial8250_read_char to allow this. Signed-off-by: Jeremy Kerr Tested-by: Eddie James Tested-by: Joel Stanley Signed-off-by: Greg Kroah-Hartman

serial: 8250: Use hrtimers for rs485 delays

2017-08-28T18:51:20Z

Previously the timers where based on the classic timers, giving a too coarse resolution on systems with configs of less than 1000 HZ. This patch changes the rs485 timers to hrtimers. Signed-off-by: Rafael Gago Castano Signed-off-by: Greg Kroah-Hartman

serial: 8250: Expose set_ldisc function

2016-11-16T09:59:38Z

Expose set_ldisc() function so that it can be overridden with a platform specific implementation. Signed-off-by: Ed Blake Signed-off-by: Greg Kroah-Hartman

serial: 8250: Add IrDA to UART capabilities

2016-11-16T09:59:38Z

Add an IrDA UART capability flag and change the type of uart_8250_port.capabilities to be u32 rather than unsigned short to accommodate the additional flag. Signed-off-by: Ed Blake Signed-off-by: Greg Kroah-Hartman

Revert "tty/serial/8250: use mctrl_gpio helpers"

2016-08-31T13:36:01Z

Serial console is broken in v4.8-rcX. Mika and I independently bisected down to commit 4ef03d328769 ("tty/serial/8250: use mctrl_gpio helpers"). Since neither author nor anyone else didn't propose a solution we better revert it for now. This reverts commit 4ef03d328769eddbfeca1f1c958fdb181a69c341. Link: https://lkml.kernel.org/r/20160809130229.GN1729@lahna.fi.intel.com Signed-off-by: Andy Shevchenko Tested-by: Heikki Krogerus Tested-by: Mika Westerberg Signed-off-by: Greg Kroah-Hartman

tty/serial/8250: use mctrl_gpio helpers

2016-06-25T21:30:42Z

This patch permits the usage for GPIOs to control the CTS/RTS/DTR/DSR/DCD/RI signals. Signed-off-by: Yegor Yefremov Signed-off-by: Greg Kroah-Hartman

serial: 8250: export get_mctrl function

2016-04-30T16:26:55Z

Exposes get_mctrl() function so that it can be overriden with platform specific implementation. Signed-off-by: Wan Ahmad Zainie Reviewed-by: Andy Shevchenko Reviewed-by: Heikki Krogerus Signed-off-by: Greg Kroah-Hartman

tty: Add software emulated RS485 support for 8250

2016-02-07T06:23:26Z

Implementation of software emulation of RS485 direction handling is based on omap_serial driver. Before and after transmission RTS is set to the appropriate value. Note that before calling serial8250_em485_init() the caller has to ensure that UART will interrupt when shift register empty. Otherwise, emultaion cannot be used. Both serial8250_em485_init() and serial8250_em485_destroy() are idempotent functions. Signed-off-by: Matwey V. Kornilov Signed-off-by: Greg Kroah-Hartman