History log of /drivers/tty/serial/serial_core.c
Revision Date Author Comments
d0afed68fb1d586034be7a7e038488e83c37a89f 14-May-2012 Alan Cox <alan@linux.intel.com> tty: Allow uart_register/unregister/register

commit 1e66cded334e6cea596c72f6f650eec351b1e959 upstream.

This is legitimate but because we don't clear the drv->state pointer in the
unregister code causes a bogus BUG().

Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=42880
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5188eeeaa673e45a22e9433bb596fef1a16e56d6 30-Jul-2009 San Mehat <san@google.com> serial_core: Add wake_peer uart operation

Add wake_peer which is called before starting UART TX. The idea here
is to provide a mechanism where we can wakeup our peer before sending
data.

Change-Id: I42e0779b635f64ca99184b45d5b028de80197491
Signed-off-by: San Mehat <san@google.com>
2f16669d322e05171c9e1cfd94f402f7399bd2a3 05-Mar-2012 Jiri Slaby <jslaby@suse.cz> TTY: remove re-assignments to tty_driver members

All num, magic and owner are set by alloc_tty_driver. No need to
re-set them on each allocation site.

pti driver sets something different to what it passes to
alloc_tty_driver. It is not a bug, since we don't use the lines
parameter in any way. Anyway this is fixed, and now we do the right
thing.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
773598357c0baf03081cf87f2b444f97744faf1e 19-Jan-2012 Simon Glass <sjg@chromium.org> serial: Fix wakeup init logic to speed up startup

The synchronize_rcu() call resulting from making every serial driver
wake-up capable (commit b3b708fa) slows boot down on my Tegra2x system
(with CONFIG_PREEMPT disabled).

But this is avoidable since it is the device_set_wakeup_enable() and then
subsequence disable which causes the delay. We might as well just make
the device wakeup capable but not actually enable it for wakeup until
needed.

Effectively the current code does this:

device_set_wakeup_capable(dev, 1);
device_set_wakeup_enable(dev, 1);
device_set_wakeup_enable(dev, 0);

We can just drop the last two lines.

Before this change my boot log says:
[ 0.227062] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[ 0.702928] serial8250.0: ttyS0 at MMIO 0x70006040 (irq = 69) is a Tegra

after:
[ 0.227264] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
[ 0.227983] serial8250.0: ttyS0 at MMIO 0x70006040 (irq = 69) is a Tegra

for saving of 450ms.

Suggested-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
97d24634daff8b83dae21cfde68553ff4997e558 20-Dec-2011 Uwe Kleine-König <u.kleine-koenig@pengutronix.de> serial: use DIV_ROUND_CLOSEST instead of open coding it

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
c0d92be6bc4fbbf6402fde2c0bc08fc4d2b58430 09-Nov-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, extract uart_port_startup

Extract ASYNC_INITIALIZED/TTY_IO_ERROR handling from uart_startup.
This will be useful for tty port helpers. These flags are handled
by the helpers instead.

So we create a new function uart_port_startup without touching these
flags there. And we keep uart_startup with the exact behavior as
before. We need that one because we start/stop the device from other
paths than open/close/hangup.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
b922e19d03a680d732b61dc8e82d9948f6f8b6c7 09-Nov-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, fill uart_port_shutdown

Let's fill the port_ops->shutdown. We will need this for hangup and
close port helpers.

We don't need to touch DTR/RTS registers in uart_port_shutdown. They
are set to off from port_close_start properly already.

Also we don't need to pin the TTY_IO_ERROR bit. This will be done in
close/hangup paths.

We leave uart_shutdown as is, because it is used (and will be) from
several paths now. Like from suspend.

The point is to not touch ASYNC_INITIALIZED bit. It will be set (and
checked) properly by the tty port helpers.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
0b1db83081599615cf7b254aebc14a2d8f6ca056 09-Nov-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, define uart_port_activate/shutdown

This is a preparation for the next patches which will move the stuff
from uart_open and uart_close/hangup here. Then we will use
tty_port_* helpers.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
1c7b13c4886f5cfaf02fb1052f65ef1a2fe88b9a 09-Nov-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, inline uart_get

We need to expand uart_get into uart_open. We need it to move on with
conversion to use tty_port_open helper. After we do this, the code
will be much more similar to what tty_port_open does.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
b39c49a05ec7322c96ec917922eae8b908d2c76f 09-Nov-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, do not touch tty->alt_speed

It is not used at all, so no need to play any games with that.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
cf75525f374dd5c49d705d9c8c3757f9aa3e9fd2 09-Nov-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, document few functions

Just put a kernel-doc comment to uart_change_pm and uart_insert_char.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
d30ccf08e8e01060288587f52a78c3ca0fcfc1fc 09-Nov-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, use tty_port_close_start helper

After the previous patches, the code is almost identical. There are
few differences in the helper code:
1) flush_buffer when flow_stopped
* when a user doesn't care about the data, delete it anyways
2) ASYNCB_INITIALIZED test before wait_until_sent_from
* obviously, there is nothing to wait for if the port is dead
3) drain_delay wait
* we don't set drain_delay

So we can use the helper now. It indeed removes a bunch of duplicated
code.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
4cb0fbfdc81f29a414583bd05a9e324f8f19984d 09-Nov-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, switch closing_wait and close_delay to jiffies

As the tty_port helpers think closing_wait and close_delay are in
jiffies and we want to use the helpers (next patches), we have to
switch the closing_wait and close_delay from ms to jiffies now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
027d7dacf73273dbe07a75b2ef5579616f17272c 09-Nov-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, cleanup include file

There are some functions (uart_handle_dcd_change, _handle_cts_change,
_insert_char) which are big enough to not be inlined. So move them
from .h to .c. We need to export them so that modules can actually use
them.

They will be even bigger when we introduce tty refcounting to them.

While at it, cleanup the "Proud member of Uglyhacks'R'US". It means,
define uart_handle_sysrq_char only when SUPPORT_SYSRQ is set.
Otherwise define it as a macro. This is needed for some arm driver
where the second parameter is undefined if expanded.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
d208a3bf77f902283894f546b6b5383202cf7882 19-Oct-2011 Doug Anderson <dianders@chromium.org> TTY: serial_core: Fix crash if DCD drop during suspend

This crash was showing up 100% of the time on Tegra CPUs when an
agetty was running on the serial port and the console was not running
on the serial port. The reason the Tegra saw it so reliably is that
the Tegra CPU internally ties DTR to DCD/DSR. That means when we
dropped DTR during suspend we would get always get an immediate DCD
drop.

The specific order of operations that were running:
* uart_suspend_port() would be called to put the uart in suspend mode
* we'd drop DTR (ops->set_mctrl(uport, 0)).
* the DTR drop would be looped back in the CPU to be a DCD drop.
* the DCD drop would look to the serial driver as a hangup
* the hangup would call uart_shutdown()
* ... suspend / resume happens ...
* uart_resume_port() would be called and run the code in the
(port->flags & ASYNC_SUSPENDED) block, which would startup the port
(and enable tx again).
* Since the UART would be available for tx, we'd immediately get
an interrupt, eventually calling transmit_chars()
* The transmit_chars() function would crash. The first crash would
be a dereference of a NULL tty member, but since the port has been
shutdown that was just a symptom.

I have proposed a patch that would fix the Tegra CPUs here (see
https://lkml.org/lkml/2011/10/11/444 - tty/serial: Prevent drop of DCD
on suspend for Tegra UARTs). However, even with that fix it is still
possible for systems that have an externally visible DCD line to see a
crash if the DCD drops at just the right time during suspend: thus
this patch is still useful.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
94abc56f4d90f289ea32a0a11d3577fcd8cb28fb 05-Sep-2011 Ning Jiang <ning.jiang@marvell.com> serial-core: power up uart port early before we do set_termios when resuming

The following patch removed uart_change_pm() in uart_resume_port():

commit 5933a161abcb8d83a2c145177f48027c3c0a8995
Author: Yin Kangkai <kangkai.yin@linux.intel.com>
serial-core: reset the console speed on resume

It will break the pxa serial driver when the system resumes from suspend mode
as it will try to set baud rate divider register in set_termios but with
clock off. The register value can not be set correctly on some platform if
the clock is disabled. The pxa driver will check the value and report the
following warning:

------------[ cut here ]------------
WARNING: at drivers/tty/serial/pxa.c:545 serial_pxa_set_termios+0x1dc/0x250()
Modules linked in:
[<c0281f30>] (unwind_backtrace+0x0/0xf0) from [<c029341c>] (warn_slowpath_common+0x4c/0x64)
[<c029341c>] (warn_slowpath_common+0x4c/0x64) from [<c029344c>] (warn_slowpath_null+0x18/0x1c)
[<c029344c>] (warn_slowpath_null+0x18/0x1c) from [<c044b1e4>] (serial_pxa_set_termios+0x1dc/0x250)
[<c044b1e4>] (serial_pxa_set_termios+0x1dc/0x250) from [<c044a840>] (uart_resume_port+0x128/0x2dc)
[<c044a840>] (uart_resume_port+0x128/0x2dc) from [<c044bbe0>] (serial_pxa_resume+0x18/0x24)
[<c044bbe0>] (serial_pxa_resume+0x18/0x24) from [<c0454d34>] (platform_pm_resume+0x40/0x4c)
[<c0454d34>] (platform_pm_resume+0x40/0x4c) from [<c0457ebc>] (pm_op+0x68/0xb4)
[<c0457ebc>] (pm_op+0x68/0xb4) from [<c0458368>] (device_resume+0xb0/0xec)
[<c0458368>] (device_resume+0xb0/0xec) from [<c04584c8>] (dpm_resume+0xe0/0x194)
[<c04584c8>] (dpm_resume+0xe0/0x194) from [<c0458588>] (dpm_resume_end+0xc/0x18)
[<c0458588>] (dpm_resume_end+0xc/0x18) from [<c02c518c>] (suspend_devices_and_enter+0x16c/0x1ac)
[<c02c518c>] (suspend_devices_and_enter+0x16c/0x1ac) from [<c02c5278>] (enter_state+0xac/0xdc)
[<c02c5278>] (enter_state+0xac/0xdc) from [<c02c48ec>] (state_store+0xa0/0xbc)
[<c02c48ec>] (state_store+0xa0/0xbc) from [<c0408f7c>] (kobj_attr_store+0x18/0x1c)
[<c0408f7c>] (kobj_attr_store+0x18/0x1c) from [<c034a6a4>] (sysfs_write_file+0x108/0x140)
[<c034a6a4>] (sysfs_write_file+0x108/0x140) from [<c02fb798>] (vfs_write+0xac/0x134)
[<c02fb798>] (vfs_write+0xac/0x134) from [<c02fb8cc>] (sys_write+0x3c/0x68)
[<c02fb8cc>] (sys_write+0x3c/0x68) from [<c027c700>] (ret_fast_syscall+0x0/0x2c)
---[ end trace 88289eceb4675b04 ]---

This patch fix the problem by adding the power on opertion back for uart
console when console_suspend_enabled is true.

Signed-off-by: Ning Jiang <ning.jiang@marvell.com>
Tested-by: Mayank Rana <mrana@codeaurora.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
55956216f4b42fefaee70060b054359d63d2afa5 29-Aug-2011 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> TTY: serial: Move mutex_unlock in uart_close function

When mutex_lock is not called, mutex_unlock is sometimes called.
This deletes unnecessary goto and makes modifications so that
mutex_unlock is called.

[ 8.304000] WARNING: at kernel/muex-debug.c:78
[ 8.304000] Modules linked in:
[ 8.304000]
[ 8.304000] Pid : 114, Comm: modprobe
[ 8.304000] CPU : 0 Not tainted (3.1.0-rc3-next-20110826 #810)
[ 8.304000]
[ 8.304000] PC is at debug_mutex_unlock+0xf4/0x120
[ 8.304000] PR is at debug_mutex_unlock+0xe6/0x120
[ 8.304000] PC : 80051114 SP : 9f02de58 SR : 400081f1 TEA : 295cf4f2
[ 8.304000] R0 : 00000001 R1 : 00000000 R2 : 0000000f R3 : 00000000
[ 8.304000] R4 : 9fc63158 R5 : 00000000 R6 : 00000001 R7 : 9fe1de78
[ 8.304000] R8 : 805c6b2c R9 : 80003920 R10 : 00000000 R11 : 805c6b2c
[ 8.304000] R12 : 80425ca0 R13 : 00000000 R14 : 9f02de58
[ 8.304000] MACH: 00000003 MACL: 00000000 GBR : 296e1678 PR : 80051106
[ 8.304000]
[ 8.304000] Call trace:
[ 8.304000] [<804236c6>] __mutex_unlock_slowpath+0x46/0x120
[ 8.304000] [<804237aa>] mutex_unlock+0xa/0x20
[ 8.304000] [<80240ed6>] uart_close+0x76/0x2c0
[ 8.304000] [<80223b98>] tty_release+0xf8/0x5c0
[ 8.304000] [<800a93a6>] lookup_object+0x26/0xa0
[ 8.304000] [<80063f6a>] call_rcu+0x8a/0xc0
[ 8.304000] [<800a944a>] put_object+0x2a/0x60
[ 8.304000] [<80003920>] arch_local_irq_restore+0x0/0x40
[ 8.304000] [<800af320>] fput+0x180/0x2c0
[ 8.304000] [<800af248>] fput+0xa8/0x2c0
[ 8.304000] [<800ab1a8>] filp_close+0x48/0xc0
[ 8.304000] [<800ab29a>] sys_close+0x7a/0x100
[ 8.304000] [<8000825a>] syscall_call+0xc/0x10
[ 8.304000] [<800ab220>] sys_close+0x0/0x100
[ 8.304000]
[ 8.304000] Code:
[ 8.304000] 8005110e: mov.l @r1, r1
[ 8.304000] 80051110: tst r1, r1
[ 8.304000] 80051112: bf 80051116
[ 8.304000] ->80051114: trapa #62
[ 8.304000] 80051116: mov.l @r8, r1
[ 8.304000] 80051118: tst r1, r1
[ 8.304000] 8005111a: bt.s 8005104c
[ 8.304000] 8005111c: mov #0, r1
[ 8.304000] 8005111e: bra 80051056
[ 8.304000]
[ 8.304000] ---[ end trace e8f8e04c313f429b ]---

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
0b058353abfcdba4403af60f06998da590ebeffe 25-Aug-2011 Jiri Slaby <jslaby@suse.cz> TTY: use tty_wait_until_sent_from_close in other drivers

Let's use the newly added helper to avoid stalls in drivers which are
not yet ported to tty_port helpers.

Those which are broken (call tty_wait_until_sent with irqs disabled)
are left untouched. They are in a deeper trouble than we are trying to
solve here. This includes amiserial, 68328serial, 68360serial and
crisv10.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
bafb0bd24d7e0e0124318625b239a55d58c757a2 25-Aug-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, move locking in uart_close

So now, when we handle CLOSING flag, there is no point to hold
port->mutex over the start of uart_close.

Yes, there are still several things to reason about:
* port->count etc is and always was protected by a spinlock
* ->stop_rx is protected by a spinlock. Otherwise it would
race with interrupts.
* uart_wait_until_sent -- that one is already called without
port->mutex from set_termios and tty_set_ldisc. Should anything
be protected there, it would be tx_empty. And by a spinlock.
8250 does this internally...

This step is needed to fix system stalls. To not create an AB-BA lock
dependency (see next patches).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
426929f8d3514d7f727b8c464d1eeeaf74b21519 25-Aug-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, use ASYNCB_CLOSING in uart_close

We need to move port->mutex locking after wait_until_sent in
uart_close (for rationale see next patches). But if we did it now, we
would introduce a race between close and open. This is exactly why
port->mutex is locked at the top of uart_close.

To avoid the race, we add ASYNCB_CLOSING to uart_close. Like every
other sane TTY driver. Thanks to tty_port_block_til_ready used in
uart_open we will have this for free. Then we can move the port->mutex
lock.

Also note that this will make the conversion to tty_port helpers
easier. They are currently handling ASYNC_CLOSING flag correctly.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
4834d028978583dfe8e1fc19f1180ceb03d8dfb7 15-Aug-2011 Jamie Iles <jamie@jamieiles.com> tty: serial8250: remove UPIO_DWAPB{,32}

Now that platforms can override the port IRQ handler and the only user
of these UPIO modes has been converted over, kill off UPIO_DWAPB and
UPIO_DWAPB32.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
906cbe1364d94da7cbf74c1d05e3e78b2883f661 14-Jul-2011 Jiri Slaby <jslaby@suse.cz> TTY: remove tty_locked

We used it really only serial and ami_serial. The rest of the
callsites were BUG/WARN_ONs to check if BTM is held. Now that we
pruned tty_locked from both of the real users, we can get rid of
tty_lock along with __big_tty_mutex_owner.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
6a3e492b6daaf7ec4dc41e51d87d2aae8ff886f2 14-Jul-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, remove tasklet for tty_wakeup

tty_wakeup can be called from any context. So there is no need to have
an extra tasklet for calling that. Hence save some space and remove
the tasklet completely.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
1f33a51d9771b34be3cb6f7fb96a325e17bbac7b 14-Jul-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, remove BTM from wait_until_sent

During the BKL removal process, the BKL was switched to tty_lock
(BTM). Now we should start pruning the BTM further. Let's start with
wait_until_sent of the serial layer. This will allow us to switch to
the tty port helpers and thus clean it up much.

In wait_until_sent there are some uport members accessed, but neither
of them is protected by BTM at the location they are set ('=>' means
function call):
* uport->fifosize (set in tty_ioctl => uart_ioctl => uart_set_info)
* uport->type (set in add_one_port prior to tty_register_device)
* uport->timeout (set usually in tty_ioctl => tty_mode_ioctl =>
tty_set_termios => uart_set_termios => uart_change_speed =>
uport->ops->set_termios => uart_update_timeout)
* call to uport->ops->tx_empty()

If the tx_empty hook needs some lock to protect accesses to registers,
it should take &uport->lock spinlock like 8250 does. Otherwise there
still might be races e.g. with ISRs.

This should also fix the issue Andreas is seeing (BTM in comparison to
BKL doesn't have any hidden functionality like unlocking during
sleeping).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
References: https://lkml.org/lkml/2011/5/25/562
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andreas Bombe <aeb@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
0055197e984e5fbe6f48f37fc50dd30254915493 17-Aug-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial, document ignoring of uart->ops->startup error

When a user has SYS_ADMIN capabilities and uart->ops->startup returns
an error in uart_startup, we silently drop the error. We then return 0
and behave as if it didn't fail. (Not quite, since we set TTY_IO_ERROR
bit and leave ASYNC_INITIALIZED bit cleared.)

This all is to allow setserial to work with improperly configured or
unconfigured ports. User can thus set port properties and reconfigure
properly.

This patch only documents this behavior.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russel King <linux@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
c831cff256c86588976e66bef7897633d534846c 20-Apr-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial_core, remove superfluous set_task_state

msleep* is guaranteed to return with TASK_RUNNING task state. And
since there is no other set_task_state in the paths of
uart_wait_until_sent, we need not to set_task_state to TASK_RUNNING.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
32ad3a77b256948a326c3f68db6acaad2b6953e7 20-Apr-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial_core, remove invalid test

tty->index (named here as line) is set up in initialize_tty_struct.
The value is checked in get_tty_driver for the found driver as:
if (device < base || device >= base + p->num)
continue;
*index = device - base;

So index/line can never be more than driver->num. Hence remove this
test from uart_open.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
e9a470f445271eb157ee860a93b062324402fc3a 18-Apr-2011 Govindraj.R <govindraj.raja@ti.com> Serial: Remove unused code.

Remove stale code in serial_core layer.

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
99edb3d10a9d384d69557bd09cc39b9ec62aa04e 30-Mar-2011 Jovi Zhang <bookjovi@gmail.com> tty: remove invalid location line in file header

remove invalid location line in each file header after location
moved from driver/char to driver/tty

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
6f5c24ad0f7619502199185a026a228174a27e68 30-Mar-2011 Jiri Slaby <jslaby@suse.cz> serial: core, remove uart_update_termios

Now, uart_update_termios is empty, so it's time to remove it. We no
longer need a live tty in .dtr_rts. So this should prune all the bugs
where tty is zeroed in port->tty during tty_port_block_til_ready.

There is one thing to note. We don't set ASYNC_NORMAL_ACTIVE now. It's
because this is done already in tty_port_block_til_ready.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
303a7a1199c20f7c9452f024a6e17bf348b6b398 30-Mar-2011 Jiri Slaby <jslaby@suse.cz> serial: core, do not set DTR/RTS twice on startup

In .dtr_rts we do:
uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS)
and call uart_update_termios. It does:
uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS)
once again. As the only callsite of uart_update_termios is .dtr_rts,
remove the uart_set_mctrl from uart_update_termios to not set it twice.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
c7d7abff40c27f82fe78b1091ab3fad69b2546f9 30-Mar-2011 Jiri Slaby <jslaby@suse.cz> serial: core, move termios handling to uart_startup

We should not fiddle with speed and cflags in .dtr_rts hook. Actually
we might not have tty at that moment already.

So move the console cflag copy and speed setup into uart_startup.
Actually the speed setup is already there, but we need to call it
unconditionally (uart_startup is called from uart_open with hw_init =
0).

This means we move uart_change_speed before dtr/rts setup in .dtr_rts.
But this should not matter as the setup should be called after
uart_change_speed anyway.
Before: After:
dtr/rts setup (dtr_rts) uart_change_speed (startup)
uart_change_speed (update_termios) dtr/rts setup (dtr_rts)
dtr/rts setup (update_termios) dtr/rts setup (update_termios)

The second setup will dismiss with the next patch.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
4fd53ef5c97ef7ce909c18bf7fb8b5cdd72b08c1 23-Mar-2011 Jiri Slaby <jslaby@suse.cz> TTY: serial_core, remove unused variable

drivers/tty/serial/serial_core.c:1980:2: warning: Value stored to 'tty' is never read
tty = port->tty;
^ ~~~~~~~~~

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
6caa76b7786891b42b66a0e61e2c2fff2c884620 14-Feb-2011 Alan Cox <alan@linux.intel.com> tty: now phase out the ioctl file pointer for good

Only oddities here are a couple of drivers that bogusly called the ldisc
helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes
away.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
20b9d17715017ae4dd4ec87fabc36d33b9de708e 14-Feb-2011 Alan Cox <alan@linux.intel.com> tiocmset: kill the file pointer argument

Doing tiocmget was such fun we should do tiocmset as well for the same
reasons

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
60b33c133ca0b7c0b6072c87234b63fee6e80558 14-Feb-2011 Alan Cox <alan@linux.intel.com> tiocmget: kill off the passing of the struct file

We don't actually need this and it causes problems for internal use of
this functionality. Currently there is a single use of the FILE * pointer.
That is the serial core which uses it to check tty_hung_up_p. However if
that is true then IO_ERROR is also already set so the check may be removed.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
5933a161abcb8d83a2c145177f48027c3c0a8995 30-Jan-2011 Yin Kangkai <kangkai.yin@linux.intel.com> serial-core: reset the console speed on resume

On some platforms, we need to restore the console speed on resume even
it was not suspended (no_console_suspend), and on others we don't have
to do that.

So don't care about the "console_suspend_enabled" and unconditionally
reset the console speed if it is a console.

This is actually a redo of ba15ab0 (Set proper console speed on resume
if console suspend is disabled) from Deepak Saxena. I also tried to
investigate more to find out if this change will break others, here is
what I've found out:

commit 891b9dd10764352926e1e107756aa229dfa2c210
Author: Jason Wang <jason77.wang@gmail.com>
serial-core: restore termios settings when resume console ports

commit ca2e71aa8cfb0056ce720f3fd53f59f5fac4a3e1
Author: Jason Wang <jason77.wang@gmail.com>
serial-core: skip call set_termios/console_start when no_console_suspend

commit 4547be7809a3b775ce750ec7f8b5748954741523
Author: Stanislav Brabec <sbrabec@suse.cz>
serial-core: resume serial hardware with no_console_suspend

commit ba15ab0e8de0d4439a91342ad52d55ca9e313f3d
Author: Deepak Saxena <dsaxena@laptop.org>
Set proper console speed on resume if console suspend is disabled

from ba15ab0, we learned that, even if the console suspend is disabled
(when no_console_suspend is set), we may still need to "reset the port
to the state it was in before we suspended."

Then with 4547be7, this piece of code is removed.

And then Jason Wang added that back in ca2e71a and 891b9dd, to fix
some breakage on OMAP3EVM platform. From ca2e71a we learned that the
"set_termios" things is actually needed by both console is suspended
and not suspended.

That's why I removed the console_suspended_enabled condition, and only
call console_start() when we actually suspeneded it.

I also noticed in this thread:
http://marc.info/?t=129079257100004&r=1&w=2, which talked about on
some platforms, UART HW will be cut power whether or not we set
no_console_suspend, and then on resume it does not work quite well. I
have a similar HW, and this patch fixed this issue, don't know if this
patch also works on their platforms.

[Update: Stanislav tested this patch on Zaurus and reported it improves the
situation. Thanks.]

CC: Greg KH <greg@kroah.com>
CC: Deepak Saxena <dsaxena@laptop.org>
CC: Jason Wang <jason77.wang@gmail.com>
CC: Stanislav Brabec <sbrabec@suse.cz>
CC: Daniel Drake <dsd@laptop.org>
Signed-off-by: Yin Kangkai <kangkai.yin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ab4382d27412e7e3e7c936e8d50d8888dfac3df8 13-Jan-2011 Greg Kroah-Hartman <gregkh@suse.de> tty: move drivers/serial/ to drivers/tty/serial/

The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>