linux-stable.git/include/linux/serial_8250.h, branch v5.6.2

tty/serial: Migrate 8250_fsl to use has_sysrq

2019-12-18T14:04:42+00:00

The SUPPORT_SYSRQ ifdeffery is not nice as:
- May create misunderstanding about sizeof(struct uart_port) between
  different objects
- Prevents moving functions from serial_core.h
- Reduces readability (well, it's ifdeffery - it's hard to follow)

In order to remove SUPPORT_SYSRQ, has_sysrq variable has been added.
Initialise it in driver's probe and remove ifdeffery.

In contrast to 8250/8250_of, legacy_serial on powerpc does fill
(struct plat_serial8250_port). The reason is likely that it's done on
device_initcall(), not on probe. So, 8250_core is not yet probed.

Propagate value from platform_device on 8250 probe - in case powepc
legacy driver it's initialized on initcall, in case 8250_of it will be
initialized later on of_platform_serial_setup().

Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Dmitry Safonov 
Link: https://lore.kernel.org/r/20191213000657.931618-6-dima@arista.com
Signed-off-by: Greg Kroah-Hartman

tty/serial/8250: use mctrl_gpio helpers

2019-06-21T08:18:43+00:00

This patch permits the usage for GPIOs to control
the CTS/RTS/DTR/DSR/DCD/RI signals.

Changed by Stefan:
Only call mctrl_gpio_init(), if the device has no ACPI companion device
to not break existing ACPI based systems. Also only use the mctrl_gpio_
functions when "gpios" is available.

Use MSR / MCR <-> TIOCM wrapper functions.

Signed-off-by: Yegor Yefremov 
Signed-off-by: Stefan Roese 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Mika Westerberg 
Tested-by: Yegor Yefremov 
Cc: Mika Westerberg 
Cc: Andy Shevchenko 
Cc: Giulio Benetti 
Cc: Yegor Yefremov 
Cc: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

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

2018-12-17T15:02:57+00:00

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()

2018-07-12T15:07:26+00:00

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

2018-04-23T08:16:50+00:00

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

2017-08-28T18:51:20+00:00

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

2016-11-16T09:59:38+00:00

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

2016-11-16T09:59:38+00:00

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"

2016-08-31T13:36:01+00:00

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