Commit Graph

104 Commits

Author SHA1 Message Date
Arnd Bergmann 3f582b8c11 serial: fix termios settings in open
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 <arnd@arndb.de>
Reported-by: Tony Luck <tony.luck@intel.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 13:47:43 -07:00
Alan Cox 74c2107759 serial: Use block_til_ready helper
Our code now rather closely resembles the helper, so switch to it.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 13:47:42 -07:00
Alan Cox 24fcc7c8cd serial: trim locking on the helpers
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 <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 13:47:42 -07:00
Alan Cox de0c8cb314 serial: add port helpers
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 <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 13:47:42 -07:00
Alan Cox 61cd8a21d8 serial: Change the wait for carrier locking
We want to push the lock/unlock into the helper functions so that we
can prepare to move to using the tty_port helper. The expansion initially
comes out a bit ugly but its worth the temporary expansion IMHO just so
we can produce a nice testable series of changes.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 13:47:42 -07:00
Alan Cox d87d9b7d19 tty: serial - fix tty referencing in set_ldisc
Pass down the ldisc number so that the drivers don't have to peek into the
tty object themselves. This lets us get rid of another case of back referencing
port to tty which we don't want (because of races versus hangup/close).

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 13:47:41 -07:00
Alan Cox 192251352f tty: serial - fix various misuses/mishandlings of port->tty
Make it robust against hang up events. In most cases we can do this simply
by passing the right things in the first place.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 13:47:41 -07:00
Alan Cox 16ae2a877b serial: Fix crash if the minimum rate of the device is > 9600 baud
In that situation if the old rate is invalid and the new rate is invalid
and the chip cannot do 9600 baud we report zero, which makes all the
drivers explode.

Instead force the rate based on min/max

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-20 15:03:29 -08:00
Stanislav Brabec 4547be7809 serial-core: resume serial hardware with no_console_suspend
Perform a tricky suspend/resume even with no_console_suspend.

With no_console_suspend, kernel skips serial port suspend/resume and the
serial hardware may remain in undefined state after resume. It actually
happens on devices that don't have BIOS that handle serial
initialization. It makes impossible to use serial console after resume.

Devices affected by this problem include:
Sharp Zaurus devices
Several PXA based ARM embedded boards

The patch does:
- Save the hardware state
- Perform buffer flush in time of its suspend call
- Tell the driver that port is suspended
- But still accept new data
- And keep console hardware in state that allows to send them

It allows to capture late console messages without breaking console
after resume.

This is just a resend of a patch discussed in these threads, as the
patch was not yet applied.

"Possible suspend/resume regression in .32-rc?" (Nov 1-5, 2009, ARM
list, later LKML)

"serial-core: resume serial hardware with no_console_suspend" (Sep
15-Oct 18, 2009, LKML & ARM lists)

Signed-off-by: Stanislav Brabec <sbrabec@suse.cz>
Tested-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Tested-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-20 15:03:29 -08:00
André Goddard Rosa 82cb7ba10d serial: cascade needless conditionals
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 15:18:04 -08:00
André Goddard Rosa 9e845abfc8 serial: fix NULL pointer dereference
If kzalloc() or alloc_tty_driver() fails, we call:
    put_tty_driver(normal = NULL).

Then:
    put_tty_driver -> tty_driver_kref_put -> kref_put(&NULL->kref, ...)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 15:18:04 -08:00
Linus Torvalds eea7e17e0e tty, serial: Fix race and NULL check in uart_close()
Commit 46d57a449a ("serial: use tty_port pointers in the core code")
contained two bugs that causes (rare) crashes:

 - the rename typoed one site

 - a NULL check was missed

Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-12 10:21:33 -07:00
Randy Dunlap 1b9894f342 serial core: fix new kernel-doc warnings
Fix new kernel-doc warnings in serial_core.[hc] files.

  Warning(include/linux/serial_core.h:485): No description found for parameter 'uport'
  Warning(include/linux/serial_core.h:485): Excess function parameter 'port' description in 'uart_handle_dcd_change'
  Warning(include/linux/serial_core.h:511): No description found for parameter 'uport'
  Warning(include/linux/serial_core.h:511): Excess function parameter 'port' description in 'uart_handle_cts_change'
  Warning(drivers/serial/serial_core.c:2437): No description found for parameter 'uport'
  Warning(drivers/serial/serial_core.c:2437): Excess function parameter 'port' description in 'uart_add_one_port'
  Warning(drivers/serial/serial_core.c:2509): No description found for parameter 'uport'
  Warning(drivers/serial/serial_core.c:2509): Excess function parameter 'port' description in 'uart_remove_one_port'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 11:24:57 -07:00
Deepak Saxena ba15ab0e8d Set proper console speed on resume if console suspend is disabled
Commit b5b82df6, from May 2007, breaks no_console_suspend on the OLPC
XO laptop. Basically what happens is that upon returning from resume,
serial8250_resume_port() will reconfigure the port for high speed
mode and all console output will be garbled, making debug of the
resume path painful. This patch modifies uart_resume_port() to
reset the port to the state it was in before we suspended.

Original patch by Marcelo Tosatti

Second patch by Deepak then reworked by Alan to fit with the tty changes
before it got submitted. Also fixed the console path to set c_i/ospeed as
some drivers require the termios fields are valid

Signed-off-by: Deepak Saxena <dsaxena@laptop.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:33 -07:00
Alan Cox 7b01478f97 serial: introduce tty krefs
Initially just use the helper and thus krefs when we set and clear the
port values.

Signed-off-by: Alan Cox <alan@linux.intel.com>
2009-09-19 13:13:33 -07:00
Alan Cox 016af53a6d serial: kill USF_CLOSING_* definitions
The serial layer for some reason uses different defines for the special
case close delays and then conditionally switches to/from the normal ones
in the ioctls.

Remove this rather pointless abstraction

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:32 -07:00
Alan Cox b58d13a021 serial: move port users helper
This little helper is now tty_port specific and useful generally so move it

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:32 -07:00
Alan Cox bdc04e3174 serial: move delta_msr_wait into the tty_port
This is used by various drivers not just serial and can be extracted
as commonality

Signed-off-by: Alan Cox <alan@linux.intel.com>
2009-09-19 13:13:31 -07:00
Alan Cox a2bceae065 serial: replace the state mutex with the tty port mutex
They cover essentially the same stuff and we can therefore fold it into the
tty_port one.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:31 -07:00
Alan Cox ccce6debb6 serial: move the flags into the tty_port field
Fortunately the serial layer was designed to use the same flag values but
with different names. It has its own SUSPENDED flag which is a free slot in
the ASYNC flags so we allocate it in the ASYNC flags instead.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:30 -07:00
Alan Cox 91312cdb4f serial: move count into the tty_port version
Remove more stuff from the serial special case code

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:29 -07:00
Alan Cox 46d57a449a serial: use tty_port pointers in the core code
Extract out a lot of the x.port. uses and also show up where there are
things left to be isolated that prevent use using the port helpers in the
serial layer at this point

Signed-off-by: Alan Cox <alan@linux.intel.com>
2009-09-19 13:13:29 -07:00
Alan Cox 5e99df561f serial: Fold closing_* fields into the tty_port ones
Remove some more serial specific use

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:28 -07:00
Alan Cox ebd2c8f6d2 serial: kill off uart_info
We moved this into uart_state, now move the fields out of the separate
structure and kill it off.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:28 -07:00
Alexey Dobriyan 833bb3046b serial: fixup /proc/tty/driver/serial after proc_fops conversion
"struct tty_driver *" lies in m->private not in v which is
SEQ_TOKEN_START which is 1 which is enough to trigger NULL dereference
next line:

	BUG: unable to handle kernel NULL pointer dereference at 000000ad
	IP: [<c040d689>] uart_proc_show+0xe/0x2b0

Noticed by Linus.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 14:50:48 -07:00