linux-toradex.git/drivers/char/n_tty.c, branch v2.6.27.12

tty: Ldisc revamp

2008-07-21T00:12:34+00:00

Move the line disciplines towards a conventional ->ops arrangement.  For
the moment the actual 'tty_ldisc' struct in the tty is kept as part of
the tty struct but this can then be changed if it turns out that when it
all settles down we want to refcount ldiscs separately to the tty.

Pull the ldisc code out of /proc and put it with our ldisc code.

Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

tty: fix BKL related leak and crash

2008-05-15T17:19:30+00:00

Enabling the BKL to be lockdep tracked uncovered the following
upstream kernel bug in the tty code, which caused a BKL
reference leak:

  ================================================
  [ BUG: lock held when returning to user space! ]
  ------------------------------------------------
  dmesg/3121 is leaving the kernel with locks still held!
  1 lock held by dmesg/3121:
   #0:  (kernel_mutex){--..}, at: [] opost+0x24/0x194

this might explain some of the atomicity warnings and crashes
that -tip tree testing has been experiencing since the BKL
was converted back to a spinlock.

Signed-off-by: Ingo Molnar 
Signed-off-by: Linus Torvalds

tty: add throttle/unthrottle helpers

2008-04-30T15:29:47+00:00

Something Arjan suggested which allows us to clean up the code nicely

Signed-off-by: Alan Cox 
Cc: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tty: The big operations rework

2008-04-30T15:29:47+00:00

- Operations are now a shared const function block as with most other Linux
  objects

- Introduce wrappers for some optional functions to get consistent behaviour

- Wrap put_char which used to be patched by the tty layer

- Document which functions are needed/optional

- Make put_char report success/fail

- Cache the driver->ops pointer in the tty as tty->ops

- Remove various surplus lock calls we no longer need

- Remove proc_write method as noted by Alexey Dobriyan

- Introduce some missing sanity checks where certain driver/ldisc
  combinations would oops as they didn't check needed methods were present

[akpm@linux-foundation.org: fix fs/compat_ioctl.c build]
[akpm@linux-foundation.org: fix isicom]
[akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build]
[akpm@linux-foundation.org: fix kgdb]
Signed-off-by: Alan Cox 
Acked-by: Greg Kroah-Hartman 
Cc: Jason Wessel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Resume TTY on SUSP and fix CRNL order in N_TTY line discipline

2008-04-30T15:29:40+00:00

Refine these behaviors in the N_TTY line discipline:

1) Handle the signal characters consistently when received in a stopped TTY
   so that SUSP (typically ctrl-Z) behaves like INTR and QUIT in resuming a
   stopped TTY.

2) Adjust the order in which the IGNCR/ICRNL/INLCR processing is applied to
   be more logical and consistent with the behavior of other Unix systems.

Signed-off-by: Joe Peterson 
Cc: Alan Cox 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tty: BKL pushdown

2008-04-30T15:29:40+00:00

- Push the BKL down into the line disciplines
- Switch the tty layer to unlocked_ioctl
- Introduce a new ctrl_lock spin lock for the control bits
- Eliminate much of the lock_kernel use in n_tty
- Prepare to (but don't yet) call the drivers with the lock dropped
  on the paths that historically held the lock

BKL now primarily protects open/close/ldisc change in the tty layer

[jirislaby@gmail.com: a couple of fixes]
Signed-off-by: Alan Cox 
Signed-off-by: Jiri Slaby 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/char/n_tty.c misannotated prototype

2008-03-30T21:20:23+00:00

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

n_tty: clean up old code to follow coding style and (mostly) checkpatch

2008-02-08T17:22:25+00:00

Signed-off-by: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix IXANY and restart after signal (e.g. ctrl-C) in n_tty line discipline

2008-02-06T18:41:09+00:00

Fix two N_TTY line discipline issues related to resuming a stopped TTY
(typically done with ctrl-S):

1) Fix handling of character that resumes a stopped TTY (with IXANY)

With "stty ixany", the TTY line discipline would lose the first character
after the stop, so typing, for example, "hi^Sthere" resulted in "hihere"
(the 't' would cause the resume after ^S, but it would then be thrown away
rather than processed as an input character).  This was inconsistent with
the behavior of other Unix systems.

2) Fix interrupt signal (e.g. ctrl-C) behavior in stopped TTYs

With "stty -ixany" (often the default), interrupt signals were ignored
in a stopped TTY until the TTY was resumed with the start char (typically
ctrl-Q), which was inconsistent with the behavior of other Unix systems.

Signed-off-by: Joe Peterson 
Cc: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tty: enable the echoing of ^C in the N_TTY discipline

2008-02-06T18:41:07+00:00

Turn on INTR/QUIT/SUSP echoing in the N_TTY line discipline (e.g.  ctrl-C
will appear as "^C" if stty echoctl is set and ctrl-C is set as INTR).

Linux seems to be the only unix-like OS (recently I've verified this on
Solaris, BSD, and Mac OS X) that does *not* behave this way, and I really
miss this as a good visual confirmation of the interrupt of a program in
the console or xterm.  I remember this fondly from many Unixs I've used
over the years as well.  Bringing this to Linux also seems like a good way
to make it yet more compliant with standard unix-like behavior.

[akpm@linux-foundation.org: coding-style fixes]
Cc: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds