Commit Graph

97 Commits

Author SHA1 Message Date
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
Alexey Dobriyan
d196a949ba proc tty: switch serial_core to ->proc_fops
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:10 -07:00
Kay Sievers
4bfe090b0a serial: struct device - replace bus_id with dev_name(), dev_set_name()
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-06 10:44:37 -08:00
David Daney
8e23fcc89c Serial: Allow port type to be specified when calling serial8250_register_port.
Add flag value UPF_FIXED_TYPE which specifies that the UART type is
known and should not be probed.  For this case the UARTs properties
are just copied out of the uart_config entry.

This allows us to keep SOC specific 8250 probe code out of 8250.c.  In
this case we know the serial hardware will not be changing as it is on
the same silicon as the CPU, and we can specify it with certainty in
the board/cpu setup code.

The alternative is to load up 8250.c with a bunch of OCTEON specific
special cases in the probing code.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02 10:19:43 -08:00
Alexander Beregalov
bc3256288b fix for tty-serial-move-port
Hi Alan

next-20081204 crashes with the following message:

BUG: unable to handle kernel paging request at ffff88007d320248
IP: [<ffffffff803de934>] uart_remove_one_port+0xef/0x111
                kfree(info);
     393:       49 8d 7d 10             lea    0x10(%r13),%rdi
     397:       e8 00 00 00 00          callq  39c <uart_remove_one_port+0xef>

Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02 10:19:42 -08:00
Alan Cox
f751928e0d tty: We want the port object to be persistent
Move the tty_port and uart_info bits around a little. By embedding the uart_info
into the uart_port we get rid of lots of corner case testing and also get the
ability to go port<->state<->info which is a bit more elegant than the current
data structures.

Downsides - we allocate a tiny bit more memory for unused ports, upside we've
removed as much code as it saved for most users..

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02 10:19:42 -08:00
Yinghai Lu
a62c413373 drivers/serial: use nr_irqs
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:06 +02:00
David S. Miller
8440838bc5 serial: fix device name reporting when minor space is shared between drivers
The multiple drivers share the minor space occupied by a particular major
number, the actual index within the device name's space is indicated by
the tty_driver->name_base + uart_port->line

Another usable formula is (uart_driver->minor - MINOR_BASE) + port->line

Use those to print the device names properly in such situations in
serial_core.c and 8250.c

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:44 -07:00
Andrew Morton
9bde10a4b8 serial-make-uart_ports-ioport-unsigned-long-fix
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:39 -07:00
Alan Cox
9e98966c7b tty: rework break handling
Some hardware needs to do break handling itself and may have partial
support only. Make break_ctl return an error code. Add a tty driver flag
so you can indicate driver hardware side break support.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-22 13:03:28 -07:00
Alan Cox
df4f4dd429 serial: use tty_port
Switch the serial_core based drivers to use the new tty_port structure.
We can't quite use all of it yet because of the dynamically allocated
extras in the serial_core layer.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20 17:12:35 -07:00
Haavard Skinnemoen
6bb0e3a59a Subject: [PATCH 1/2] serial: Add flush_buffer() operation to uart_ops
Serial drivers using DMA (like the atmel_serial driver) tend to get very
confused when the xmit buffer is flushed and nobody told them.  They
also tend to spew a lot of garbage since the DMA engine keeps running
after the buffer is flushed and possibly refilled with unrelated data.

This patch adds a new flush_buffer operation to the uart_ops struct,
along with a call to it from uart_flush_buffer() right after the xmit
buffer has been cleared. The driver can implement this in order to
syncronize its internal DMA state with the xmit buffer when the buffer
is flushed.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20 17:12:34 -07:00
Guennadi Liakhovetski
7ca796f492 serial: fix serial_match_port() for dynamic major tty-device numbers
As reported by Vipul Gandhi, the current serial_match_port() doesn't work
for tty-devices using dynamic major number allocation.  Fix it.

It oopses if you suspend a serial port with _dynamic_ major number.  ATM,
I think, there's only the drivers/serial/jsm/jsm_driver.c driver, that
does it in-tree.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Tested-by: Vipul Gandhi <vcgandhi1@aol.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04 10:40:04 -07:00
Linus Torvalds
edeb280e49 Fix uart_set_ldisc() function type
Commit 64e9159f5d ("serial_core:
uart_set_ldisc infrastructure") introduced the ability for low-level
serial drivers to be informed when the tty ldisc changes.

However, the actual tty-layer function that does this callback for
serial devices was declared with the wrong type, having a spurious and
unused 'ldisc' argument.

This fixed the resulting compiler warning by just removing it.

Acked-by: Blithering Idiot <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-04 10:35:03 -07:00
Alan Cox
64e9159f5d serial_core: uart_set_ldisc infrastructure
The tty layer provides a callback that is used when the line discipline
is changed. Some hardware uses this to configure hardware specific
features such as IrDA mode on serial ports. Unfortunately the serial
layer does not provide this feature or pass it down to drivers.

Blackfin used to hack around this by rewriting the tty ops, but those are
now properly shared and const so the hack fails. Instead provide the
proper operations.

This change plus a follow up from the Blackfin guys is needed to avoid
blackfin losing features in this release.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-03 08:20:17 -07:00
Arjan van de Ven
03a74dcc7e serial: fix enable_irq_wake/disable_irq_wake imbalance in serial_core.c
enable_irq_wake() and disable_irq_wake() need to be balanced.  However,
serial_core.c calls these for different conditions during the suspend and
resume functions...

This is causing a regular WARN_ON() as found at
http://www.kerneloops.org/search.php?search=set_irq_wake

This patch makes the conditions for triggering the _wake enable/disable
sequence identical.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24 09:56:11 -07:00
Tetsuo Handa
55d7b68996 serial: access after NULL check in uart_flush_buffer()
I noticed that

  static void uart_flush_buffer(struct tty_struct *tty)
  {
  	struct uart_state *state = tty->driver_data;
  	struct uart_port *port = state->port;
  	unsigned long flags;

  	/*
  	 * This means you called this function _after_ the port was
  	 * closed.  No cookie for you.
  	 */
  	if (!state || !state->info) {
  		WARN_ON(1);
  		return;
  	}

is too late for checking state != NULL.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-08 10:46:55 -07:00
Alan Cox
f34d7a5b70 tty: The big operations rework
- 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 <alan@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:47 -07:00
Alan Cox
23d22cea85 serial: switch the serial core to int put_char methods
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:47 -07:00
Alan Cox
e523844260 serial_core: Prepare for BKL push down
Instead of checking for the BKL in these methods, take it ourselves.  That
avoids propogating it into the serial drivers and we can then fix them later
on.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Alan Cox
eb424fd21c uart_get_baud_rate: stop mangling termios
Russell King noticed this one: We have to avoid replacing B0 when we pick a
baud rate for a "hung up" port.  Ugly but the proper fix is in the tty layer
and means changing the tty<->serial interfaces so we will defer that for now.

[akpm@linux-foundation.org: fix uninitialised var]
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:30 -07:00
Alan Stern
74081f8667 PM: Fix misuse of wakeup flag accessors in serial core
This patch (as1059) fixes a mistake in the way the serial core
initializes a device's wakeup settings.  It should use the accessor
routine instead of relying on a macro producing an lvalue.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-19 19:10:25 -07:00
Andrew Morton
4a1b5502d4 kgdb: Kconfig fix
ERROR: "uart_parse_options" [drivers/serial/serial_core.ko] undefined!

Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 20:05:42 +02:00
Jason Wessel
f2d937f3bf consoles: polling support, kgdboc
polled console handling support, to access a console in an irq-less
way while in debug or irq context.

absolutely zero impact as long as CONFIG_CONSOLE_POLL is disabled.
(which is the default)

[ jan.kiszka@siemens.com: lots of cleanups ]
[ mingo@elte.hu: redesign, splitups, cleanups. ]

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-17 20:05:37 +02:00
Denis Cheng
922f9cfa79 fs/char_dev.c: chrdev_open marked static and removed from fs.h
There is an outdated comment in serial_core.c also fixed.

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:42 -08:00
Alan Cox
a46c999424 serial_core: bring mostly into line with coding style
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:25 -08:00
Alan Cox
6d4d67beb9 serial: speed setup failure reporting
Invalid speeds are forced to 9600. Update the code for this to encode new
style baud rates properly.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:10 -08:00
Russell King
c8c6bfa39d serial: avoid stalling suspend if serial port won't drain
Some ports seem to be unable to drain their transmitters on shut down.  Such a
problem can occur if the port is programmed for hardware imposed flow control,
characters are in the FIFO but the CTS signal is inactive.

Normally, this isn't a problem because most places where we wait for the
transmitter to drain have a time-out.  However, there is no timeout in the
suspend path.

Give a port 30ms to drain; this is an arbitary value chosen to avoid long
delays if there are many such ports in the system, while giving a reasonable
chance for a single port to drain.  Should a port not drain within this
timeout, issue a warning.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:10 -08:00
Russell King
9d778a6937 serial: avoid waking up closed serial ports on resume
When we boot, serial ports remain in low power mode until they're used either
by userspace or for the kernel console.

However, if you suspend the system, and then resume, all serial ports will be
taken out of low power mode.  This is bad news for embedded devices where this
can mean higher power consumption.

Only bring a serial port out of low power mode if the port is being used as
the kernel console, or is in use by userspace.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:09 -08:00
Yinghai Lu
c3e4642be7 serial: keep the DTR setting for serial console.
with reverting "x86, serial: convert legacy COM ports to platform devices",
we will have the serial console before the port is probled again.

uart_add_one_port==>uart_configure_port==>set_mcttrl(port, 0) will clear
the DTR setting by uart_set_options().  then I will lose my output from
serial console again.

So try to keep DTR in uart_configure_port()

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <ak@suse.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:09 -08:00
Alan Cox
149b36eae2 serial: stop passing NULL to functions that expect data
Earlier patches have removed the checking for old v new differences from the
USB drivers so we can now pass in a valid blank old termios so that we don't
to fill the drivers with magic hacks for console support

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-25 12:18:40 -07:00
Andres Salomon
8f4ce8c32f serial: turn serial console suspend a boot rather than compile time option
Currently, there's a CONFIG_DISABLE_CONSOLE_SUSPEND that allows one to stop
the serial console from being suspended when the rest of the machine goes
to sleep.  This is incredibly useful for debugging power management-related
things; however, having it as a compile-time option has proved to be
incredibly inconvenient for us (OLPC).  There are plenty of times that we
want serial console to not suspend, but for the most part we'd like serial
console to be suspended.

This drops CONFIG_DISABLE_CONSOLE_SUSPEND, and replaces it with a kernel
boot parameter (no_console_suspend).  By default, the serial console will
be suspended along with the rest of the system; by passing
'no_console_suspend' to the kernel during boot, serial console will remain
alive during suspend.

For now, this is pretty serial console specific; further fixes could be
applied to make this work for things like netconsole.

Signed-off-by: Andres Salomon <dilinger@debian.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:19 -07:00
Guennadi Liakhovetski
b3b708fa27 wake up from a serial port
Enable wakeup from serial ports, make it run-time configurable over sysfs,
e.g.,

echo enabled > /sys/devices/platform/serial8250.0/tty/ttyS0/power/wakeup

Requires

# CONFIG_SYSFS_DEPRECATED is not set

Following suggestions from Alan and Russell moved the may_wake_up checks
to serial_core.c. This time actually tested - it does even work. Could
someone, please, verify, that put_device after device_find_child is
correct?

Also would be nice to test with a Natsemi UART, that can wake up the system,
if such systems exist.

For this you just have to apply the patch below, issue the above "echo"
command to one of your Natsemi port, suspend and resume your system, and
verify that your Natsemi port still works.  If you are actually capable of
waking up the system from that port, would be nice to test that as well.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:50 -07:00