linux.git/drivers/serial/serial_core.c, branch v2.6.37

BKL: remove extraneous #include

2010-11-17T16:59:32+00:00

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Linus Torvalds

tty: Make tiocgicount a handler

2010-10-22T17:20:04+00:00

Dan Rosenberg noted that various drivers return the struct with uncleared
fields. Instead of spending forever trying to stomp all the drivers that
get it wrong (and every new driver) do the job in one place.

This first patch adds the needed operations and hooks them up, including
the needed USB midlayer and serial core plumbing.

Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

serial-core: restore termios settings when resume console ports

2010-10-22T17:20:02+00:00

The commit 4547be7 rewrites suspend and resume functions. According
to this rewrite, when a serial port is a printk console device and
can suspend(without set no_console_suspend flag), it will definitely
call set_termios function during its resume, but parameter termios
isn't initialized, this will pass an unpredictable config to the
serial port. If this serial port is not a userspace opened tty device
, a suspend and resume action will make this serial port unusable.
I.E. ttyS0 is a printk console device, ttyS1 or keyboard+display is
userspace tty device, a suspend/resume action will make ttyS0
unusable.

If a serial port is both a printk console device and an opened tty
device, this issue can be overcome because it will call set_termios
again with the correct parameter in the uart_change_speed function.

Refer to the deleted content of commit 4547be7, revert parts relate
to restore settings into parameter termios. It is safe because if
a serial port is a printk console only device, the only meaningful
field in termios is c_cflag and its old config is saved in
uport->cons->cflag, if this port is also an opened tty device,
it will clear uport->cons->cflag in the uart_open and the old config
is saved in tty->termios.

Signed-off-by: Jason Wang 
Acked-by: Stanislav Brabec 
Signed-off-by: Greg Kroah-Hartman

serial-core: skip call set_termios/console_start when no_console_suspend

2010-10-22T17:20:01+00:00

The commit 4547be7 rewrites suspend and resume functions, this
introduces a problem on the OMAP3EVM platoform. when the kernel boots
with no_console_suspend and we suspend the kernel, then resume it,
the serial console will be not usable. This problem should be common
for all platforms.
The cause for this problem is that when enter suspend, if we choose
no_console_suspend, the console_stop will be skiped. But in resume
function, the console port will be set to uninitialized state by
calling set_termios function and the console_start is called without
checking whether the no_console_suspend is set, Now fix it.

Signed-off-by: Jason Wang 
Acked-by: Stanislav Brabec 
Signed-off-by: Greg Kroah-Hartman

tty: untangle locking of wait_until_sent

2010-08-10T20:47:43+00:00

Some wait_until_sent versions require the big
tty mutex, others don't and some callers of
wait_until_sent already hold it while other don't.
That leads to recursive use of the BTM in these
functions, which we're trying to get rid of.

This turns all cleans up the locking there so
that the driver's wait_until_sent function
never takes the BTM itself if it is already
called with that lock held.

Signed-off-by: Arnd Bergmann 
Cc: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

tty: replace BKL with a new tty_lock

2010-08-10T20:47:43+00:00

As a preparation for replacing the big kernel lock
in the TTY layer, wrap all the callers in new
macros tty_lock, tty_lock_nested and tty_unlock.

Signed-off-by: Arnd Bergmann 
Cc: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

serial: fix termios settings in open

2010-08-10T20:47:43+00:00

Move termios initialization in open into uart_dtr_rts to make sure
it always gets called when necessary. Based on a suggestion from
Alan Cox.

Alan writes:
Ok this sort of makes sense. Something isn't getting initialised and both
getty and minicom will do a termios set which is sorting it out.
This is occurring because the generic block_til_ready sets
ASYNCB_NORMAL_ACTIVE so the termios updating gets skipped.

This patch should cure it and then we can think about doing it more
elegantly by getting the serial layer to use tty_port_open, kfifo and
the like and removing the tons of repeated crap in all the drivers.

Signed-off-by: Arnd Bergmann 
Reported-by: Tony Luck 
Cc: Alan Cox 
Cc: Tony Luck 
Signed-off-by: Greg Kroah-Hartman

serial: Use block_til_ready helper

2010-08-10T20:47:42+00:00

Our code now rather closely resembles the helper, so switch to it.

Signed-off-by: Alan Cox 
Cc: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

serial: trim locking on the helpers

2010-08-10T20:47:42+00:00

The port mutex protects port->tty, but these paths never need to walk from
port->tty. They do need the low level lock as the API expects that but they
already also take it.

Thus we can drop the extra mutex lock calls here.

Signed-off-by: Alan Cox 
Cc: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

serial: add port helpers

2010-08-10T20:47:42+00:00

We can make this the same as the ones that will be needed by the tty_port
helper logic that we want to move to but still call them from the existing
code base.

Signed-off-by: Alan Cox 
Cc: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman