linux-stable.git/drivers/char/tty_ioctl.c, branch linux-2.6.26.y

removed unused var real_tty on n_tty_ioctl()

2008-06-23T17:36:47+00:00

I noted that the 'struct tty_struct *real_tty' is not used in this
function, so I removed the code about 'real_tty'.

Signed-off-by: Gustavo Fernando Padovan 
Acked-by: Alan Cox 
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

tty/serial: lay the foundations for the next set of reworks

2008-04-30T15:29:45+00:00

- Stop drivers calling their own flush method indirectly, it obfuscates code
  and it will change soon anyway

- A few more lock_kernel paths temporarily needed in some driver internal
  waiting code

- Remove private put_char method that does a write call for one char - we
  have that anyway

- Most but not yet all of the termios copy under lock fixing (some has other
  dependencies to follow)

- Note a few locking bugs in drivers found in the process

- Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to
  fix the termios locking

Signed-off-by: Alan Cox 
Cc: Jiri Slaby 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tty_ioctl: soft carrier handling

2008-04-30T15:29:41+00:00

First cut at moving the soft carrier handling knowledge entirely into the core
code.  One or two drivers still needed to snoop these functions to track
CLOCAL internally.  Instead make TIOCSSOFTCAR generate the same driver calls
as other termios ioctls changing the clocal flag.  This allows us to remove
any driver knowledge and special casing.  Also while we are at it we can fix
the error handling.

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

tty_ioctl: locking for tty_wait_until_sent

2008-04-30T15:29:41+00:00

This function still depends on the big kernel lock in some cases.  Push
locking into the function ready for removal of the BKL from ioctl call paths.

Signed-off-by: Alan Cox 
Cc: Andi Kleen 
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

tty_ioctl: drag screaming into compliance with the coding style

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

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

pl2303: Fix mode switching regression

2008-01-09T00:16:34+00:00

Cleaning out all the incorrect 'no change made' checks for termios
settings showed up a problem with the PL2303. The hardware here seems to
lose sync and bits if you tell it to make no changes. This shows up with
a real world application.

To fix this the driver check for meaningful hardware changes is restored
but doing the tests correctly and as a tty layer function so it doesn't
get duplicated wrongly everywhere if other drivers turn out to need it.

Signed-off-by: Alan Cox 
Tested-by: Mirko Parthey 
Signed-off-by: Linus Torvalds

tty: fix logic change introduced by wait_event_interruptible_timeout()

2007-12-23T20:54:37+00:00

Commit 5a52bd4a2dcb570333ce6fe2e16cd311650dbdc8 introduced a subtle logic
change in tty_wait_until_sent().  The original version would only error out
of the 'do { ...  } while (timeout)' loop if signal_pending() evaluated to
true; a timeout or break due to an empty buffer would fall out of the loop
and into the tty->driver->wait_until_sent handling.  The current
implementation will error out on either a pending signal or an empty
buffer, falling through to the tty->driver->wait_until_sent handling only
on a timeout.

The ->wait_until_sent() will not be reached if the buffer empties before
timeout jiffies have elapsed.  This behavior differs from that prior to commit
5a52bd4a2dcb570333ce6fe2e16cd311650dbdc8.

I turned this up while using a little serial download utility to bootstrap an
ARM-based eval board.  The util worked fine on 2.6.22.x, but consistently
failed on 2.6.23.x.  Once I'd determined that, I narrowed things down with git
bisect, and found the above difference in logic in tty_wait_until_sent() by
inspection.

This change reverts the logic flow in tty_wait_until_sent() to match that
prior to the aforementioned commit.

Signed-off-by: Cory T. Tusar 
Cc: Alan Cox 
Acked-by: Jiri Slaby 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds