linux-toradex.git/Documentation/serial, branch v4.19-rc5

tty: n_gsm: do not send/receive in ldisc close path

2017-06-03T09:48:52+00:00

gsm_cleanup_mux() is called in the line discipline close path which
is called at tty_release() time. At this stage the tty is no longer
operational enough to send any frames. Sending close frames is
therefore not possible and waiting for their answers always times
out.

This patch removes sending close messages and waiting for their answers
from the tty_release path.

This patch makes explicit what previously implicitly had been the case
already: We are not able to tell the modem that we are about to close
the multiplexer on our side. This means the modem will stay in
multiplexer mode and re-establishing the multiplexer later fails. The
only way for userspace to work around this is to manually send a close
frame in N_TTY mode after closing the mux.

Signed-off-by: Sascha Hauer 
Signed-off-by: Greg Kroah-Hartman

Documentation: rs485: Do not define manually the ioctl

2016-08-18T17:08:33+00:00

It is not a very good practice to define the IOCTL manually instead of
using the header file.

Fix it on the documentation example.

Signed-off-by: Ricardo Ribalda Delgado 
Signed-off-by: Jonathan Corbet

Merge tag 'tty-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2016-05-21T03:57:27+00:00

Pull tty and serial driver updates from Greg KH:
 "Here's the large TTY and Serial driver update for 4.7-rc1.

  A few new serial drivers are added here, and Peter has fixed a bunch
  of long-standing bugs in the tty layer and serial drivers as normal.
  Full details in the shortlog.

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

* tag 'tty-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (88 commits)
  MAINTAINERS: 8250: remove website reference
  serial: core: Fix port mutex assert if lockdep disabled
  serial: 8250_dw: fix wrong logic in dw8250_check_lcr()
  tty: vt, finish looping on duplicate
  tty: vt, return error when con_startup fails
  QE-UART: add "fsl,t1040-ucc-uart" to of_device_id
  serial: mctrl_gpio: Drop support for out1-gpios and out2-gpios
  serial: 8250dw: Add device HID for future AMD UART controller
  Fix OpenSSH pty regression on close
  serial: mctrl_gpio: add IRQ locking
  serial: 8250: Integrate Fintek into 8250_base
  serial: mps2-uart: add support for early console
  serial: mps2-uart: add MPS2 UART driver
  dt-bindings: document the MPS2 UART bindings
  serial: sirf: Use generic uart-has-rtscts DT property
  serial: sirf: Introduce helper variable struct device_node *np
  serial: mxs-auart: Use generic uart-has-rtscts DT property
  serial: imx: Use generic uart-has-rtscts DT property
  doc: DT: Add Generic Serial Device Tree Bindings
  serial: 8250: of: Make tegra_serial_handle_break() static
  ...

serial: doc: Use port->state instead of info

2016-05-14T16:18:25+00:00

As of commit ebd2c8f6d2ec4012 ("serial: kill off uart_info"), the
circular transmission buffer is part of struct uart_state instead of
struct uart_info. Make it clear this structure is pointed to from struct
uart_port.

Change 'circ' to 'circ_buf' to match the structure name while we're at
it.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jonathan Corbet

serial: doc: Always refer to tty_port->mutex

2016-05-14T16:18:19+00:00

Stop referring to the mutex member of the tty_port struct as
'port->mutex', as 'port' is ambiguous, and usually refers to the
uart_port struct in this document.  Use 'tty_port->mutex' instead,
following the single existing use.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jonathan Corbet

Fix OpenSSH pty regression on close

2016-05-01T20:22:54+00:00

OpenSSH expects the (non-blocking) read() of pty master to return
EAGAIN only if it has received all of the slave-side output after
it has received SIGCHLD. This used to work on pre-3.12 kernels.

This fix effectively forces non-blocking read() and poll() to
block for parallel i/o to complete for all ttys. It also unwinds
these changes:

1) f8747d4a466ab2cafe56112c51b3379f9fdb7a12
   tty: Fix pty master read() after slave closes

2) 52bce7f8d4fc633c9a9d0646eef58ba6ae9a3b73
   pty, n_tty: Simplify input processing on final close

3) 1a48632ffed61352a7810ce089dc5a8bcd505a60
   pty: Fix input race when closing

Inspired by analysis and patch from Marc Aurele La France 

Reported-by: Volth 
Reported-by: Marc Aurele La France 
BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=52
BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=2492
Signed-off-by: Brian Bloniarz 
Reviewed-by: Peter Hurley 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial: doc: .break_ctl() may sleep

2016-04-16T16:43:12+00:00

break_ctl() is not called from any sort of atomic context, so there is no
problem with it sleeping.

Reported-by: Peter Hurley 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jonathan Corbet

serial: doc: .(un)throttle() are serialized by the tty layer

2016-04-15T21:59:12+00:00

Document that .(un)throttle() are serialized with each other, and with
termios modification by the tty layer.

Reported-by: Peter Hurley 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jonathan Corbet

serial: doc: .(un)throttle() depends on hardware assisted flow control

2016-04-15T21:59:06+00:00

Document that .throttle() and .unthrottle() are relevant only if
hardware assisted flow control is enabled.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jonathan Corbet

serial: doc: Re-add paragraph documenting uart_console_write()

2016-04-15T21:59:01+00:00

Commit 834392a7d92677ff ("serial: doc: Un-document non-existing
uart_write_console()") removed a paragraph about a helper function that
seemed to never exist.

Peter Hurley pointed out that the function does exist, but is called
differently. Re-add the paragraph, with the function name corrected.

Fixes: 834392a7d92677ff ("serial: doc: Un-document non-existing uart_write_console()")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jonathan Corbet