per CodingStyle we should have those braces, no
functional changes.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 0324a821.

That commit tried to fix a deadlock problem when using
hci_ldisc, but it turns out the bug was in hci_ldsic
all along where it was calling ->write() from within
->write_wakeup() callback.

The problem is that ->write_wakeup() was called with
port lock held and ->write() tried to grab the same
port lock.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In (efe2f29e kgdboc,kdb: Allow kdb to work on a non open console port)
support was added to directly use the "write_char" functions when
doing kdb over a non-open console port.  This is great, but it ends up
bypassing the normal code in uart_console_write() that adds a carriage
return before any newlines.

There appears to have been a trend to add this support directly in
some console driver's poll_put_char() functions.  This had a few side
effects, including:
- In this case we were doing LFCR, not CRLF.  This was fixed in
  uart_console_write() back in (d358788f [SERIAL] kernel console should
  send CRLF not LFCR)
- Not all serial drivers had the LFCR code in their poll_put_char()
  functions.  In my case I was running serial/samsung.c which lacked
  it.

I've moved the handling to uart_poll_put_char() to fix the above
problems.  Now when I use kdb (and don't point console= to the same
UART) I no longer get:

[0]kdb>
       [0]kdb>
              [0]kdb>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use del_timer_sync to ensure that the timer is stopped on all CPUs before
the driver exists.

This change was suggested by Thomas Gleixner.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
declarer name module_exit;
identifier ex;
@@

module_exit(ex);

@@
identifier r.ex;
@@

ex(...) {
  <...
- del_timer
+ del_timer_sync
    (...)
  ...>
}
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The mux driver is anomalous among all the serial drivers that can
define SUPPORT_SYSRQ because it can, with some configs, set
SUPPORT_SYSRQ when SERIAL_CORE_CONSOLE is not set.

Not only does this impose a pointless (but tiny) runtime overhead for
such configs but, more significantly, it adds needless complexity when
doing a code review to check for unexpected side effects of any
changes to the serial core.

This is (cross-)compile tested only because I do not have any PA-RISC
hardware.
Signed-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

According to the platform data for the legacy-C initialisation of sh-sci
for the r8a7779 SoC and my own testing the SCIx_SH4_SCIF_REGTYPE bit of
scscr needs to be set.
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In the same manner as 8250_pci, 8250_dw needs some
baytrail specific quirks to be used. The reference
clock needs to be adjusted before divided in order
to have the minimum error rate on the baudrate.

The specific byt set termios function is stored in
the driver_data field of the acpi device id via the
dw8250_acpi_desc structure.

Remove the uartclk field which is no longer delivered
as driver data.
Signed-off-by: NLoic Poulain <loic.poulain@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This will additionally show the specific UART device instead of the
general module name. This cames in handy so check for the interupts of
a specific device if there are several of them.
Signed-off-by: NAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit f4f653e9.

Jiri writes:
	No, please drop this one. We need a better solution as it turned
	out that some boxes need 16k loops and it will increase with new
	processors :(.

Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Pluskal <mpluskal@suse.com>
Cc: Takashi Iwai <tiwai@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A recent commit ef2889f7 "serial: pl011:
Move uart_register_driver call to device probe" introduced a regression,
causing the pl011 driver to Oops if more than 1 port have been probed. Fix
the Oops by only calling uart_unregister_driver() once after the last port
has been removed.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is memleak in alloc_pid:
------------------------------
unreferenced object 0xd3453a80 (size 64):
  comm "adbd", pid 1730, jiffies 66363 (age 6586.950s)
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 40 c2 f6 d5 00 d3 25 c1 59 28 00 00  ....@.....%.Y(..
  backtrace:
    [<c1a6f15c>] kmemleak_alloc+0x3c/0xa0
    [<c1320546>] kmem_cache_alloc+0xc6/0x190
    [<c125d51e>] alloc_pid+0x1e/0x400
    [<c123d344>] copy_process.part.39+0xad4/0x1120
    [<c123da59>] do_fork+0x99/0x330
    [<c123dd58>] sys_fork+0x28/0x30
    [<c1a89a08>] syscall_call+0x7/0xb
    [<ffffffff>] 0xffffffff

the leak is due to unreleased pid->count, which execute in function:
get_pid()(pid->count++) and put_pid()(pid->count--).

The race condition as following:
task[dumpsys]               task[adbd]
in disassociate_ctty()      in tty_signal_session_leader()
-----------------------     -------------------------
tty = get_current_tty();
// tty is not NULL
...
spin_lock_irq(&current->sighand->siglock);
put_pid(current->signal->tty_old_pgrp);
current->signal->tty_old_pgrp = NULL;
spin_unlock_irq(&current->sighand->siglock);

                            spin_lock_irq(&p->sighand->siglock);
                            ...
                            p->signal->tty = NULL;
                            ...
                            spin_unlock_irq(&p->sighand->siglock);

tty = get_current_tty();
// tty NULL, goto else branch by accident.
if (tty) {
    ...
    put_pid(tty_session);
    put_pid(tty_pgrp);
    ...
} else {
    print msg
}

in task[dumpsys], in disassociate_ctty(), tty is set NULL by task[adbd],
tty_signal_session_leader(), then it goto else branch and lack of
put_pid(), cause memleak.

move spin_unlock(sighand->siglock) after get_current_tty() can avoid
the race and fix the memleak.
Signed-off-by: NZhang Jun <jun.zhang@intel.com>
Signed-off-by: NChen Tingjie <tingjie.chen@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The 8250 driver now reports many of these:
  serial8250: too much work for irq4
These messages turned out to be common these days with a use of
virtualization. I tried to increase the limit of processed characters
in commit e7328ae1 (serial: 8250,
increase PASS_LIMIT) in 2011. It was raised from 256 to 512, but it is
still not enough, apparently.

So disable the warning unless somebody turns on DEBUG (or
DYNAMIC_DEBUG _and_ the message).
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Reported-by: NMartin Pluskal <mpluskal@suse.com>
Reported-by: NTakashi Iwai <tiwai@suse.com>
Tested-by: NTakashi Iwai <tiwai@suse.de>
References: https://bugzilla.novell.com/show_bug.cgi?id=868394Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The lack of pm_runtime_resume handling for the device state leads into
device wake-up interrupts not working after a while for runtime PM.

Also, serial-omap is confused about the use of device_may_wakeup.
The checks for device_may_wakeup should only be done for suspend and
resume, not for pm_runtime_suspend and pm_runtime_resume. The wake-up
events for PM runtime should always be enabled.

The lack of pm_runtime_resume handling leads into device wake-up
interrupts not working after a while for runtime PM.

Rather than try to patch over the issue of adding complex tests to
the pm_runtime_resume, let's fix the issues properly:

1. Make serial_omap_enable_wakeup deal with all internal PM state
   handling so we don't need to test for up->wakeups_enabled elsewhere.

   Later on once omap3 boots in device tree only mode we can also
   remove the up->wakeups_enabled flag and rely on the wake-up
   interrupt enable/disable state alone.

2. Do the device_may_wakeup checks in suspend and resume only,
   for runtime PM the wake-up events need to be always enabled.

3. Finally just call serial_omap_enable_wakeup and make sure we
   call it also in pm_runtime_resume.

4. Note that we also have to use disable_irq_nosync as serial_omap_irq
   calls pm_runtime_get_sync.

Fixes: 2a0b965c (serial: omap: Add support for optional wake-up)
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: NTony Lindgren <tony@atomide.com>
Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When a serial port is closed, uart_close() takes care of shutting down the
hardware, and powering it down.

When a serial port is unbound while in use, uart_close() bypasses all of
this, as this is supposed to be done through uart_hangup() (invoked via
tty_vhangup() in uart_remove_one_port()).

However, uart_hangup() does not set the hardware's power state, leaving it
powered up.  This may also lead to unbounded nesting counts in clock and
power management, depending on their internal implementation.

Make sure to power down the port in uart_hangup(), except when the port is
used as a serial console.

For serial consoles, this operation must be postponed until after the port
becomes completely unused. This case is not fixed yet, as it depends on a
(future) fix for the tty->count vs. port->count imbalance on failed
uart_open().

After this, the module clock used by the sh-sci driver is disabled on
unbind while the serial port is in use.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The amba-pl011.c driver sets DMA burst size equal to FIFO trigger level.
If now exactly DMA burst size bytes are received, the DMAC will retrieve
them all and no Rx timeout interrupt will be generated. To fix that set
the burst size to half the FIFO trigger level.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As far as I know the Timberdale chip was only used as a companion for
Intel Atom E600 series processors. As such, its drivers are only
useful on X86_32.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver, like several others, uses the upper bits of the character
to track both real and dummy state. Unfortunately it neglects to mask
these bits properly when passing the character data around. This means
neither break detection nor sysrq character handling work correctly.

This patch adds the requires masking and has been tested to confirm
that it correctly handles magic sysrq sequences on ST's B2020 board.
Signed-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 63e3ad32,
since this not works as expected and produce runtime error:

BUG: sleeping function called from invalid context at drivers/tty/serial/clps711x.c:379
in_atomic(): 0, irqs_disabled(): 128, pid: 287, name: mount
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the serial_core ring buffer empties just as the tty layer receives
an XOFF, then start_tx will never be called when the tty layer
receives an XON as the serial_core ring buffer is empty.  This will
possibly leave a few bytes trapped in the fifo for drivers that
disable the transmitter when flow controlled.
Signed-off-by: NSeth Bollinger <sethb@digi.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Wolfram Sang pointed out that "efm32,$device" is non-standard. So use the
common scheme and prefix device with "efm32-". The old compatible string
is left in place until arch/arm/boot/dts/efm32* is fixed.
Reported-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NSanjay Singh Rawat <sanjay.rawat@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The firmware can notify us when new input data is available, so
let's make sure we wakeup the HVC thread in that case.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Store and log all PIDs with reference to the initial PID namespace and
use the access functions task_pid_nr() and task_tgid_nr() for task->pid
and task->tgid.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
(informed by ebiederman's c776b5d2)
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>

Two cpufreq notifiers CPUFREQ_RESUMECHANGE and CPUFREQ_SUSPENDCHANGE have
not been used for some time, so remove them to clean up code a bit.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
[rjw: Changelog]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Provided that the SER_RS485_RX_DURING_TX flag is not set, empty the
RX FIFO to prevent reading back the transmitted data.
Signed-off-by: NDimitris Lampridis <dlampridis@logikonlabs.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make sure that serial_omap_stop_rx() also disables RDI (Receiver Data Interrupt),
otherwise the interrupt handler will call serial_omap_rdi() to read the new data,
resulting in the transmission being echoed back.

When the half-duplex transmission is complete, in order to reverse the effects of
serial_omap_stop_rx(), we should re-enable:

  * the RX interrupts _without_ overwriting up->ier

  * the UART_LSR_DR bit of the up->port.read_status_mask
Signed-off-by: NDimitris Lampridis <dlampridis@logikonlabs.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add missing newlines and coalesce formats.
Realign arguments.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms@verge.net.au>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms@verge.net.au>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms@verge.net.au>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make banner const while we're at it
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: NSimon Horman <horms@verge.net.au>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When unbinding a serial driver that's being used as a serial console,
the kernel may crash with a NULL pointer dereference in a uart_*() function
called from uart_close () (e.g. uart_flush_buffer() or
uart_chars_in_buffer()).

To fix this, let uart_close() check for port->count == 0. If this is the
case, bail out early. Else tty_port_close_start() will make the port
counts inconsistent, printing out warnings like

    tty_port_close_start: tty->count = 1 port count = 0.

and

    tty_port_close_start: count = -1

and once uport == NULL, it will also crash.

Also fix the related crash in pr_debug() by checking for a non-NULL uport
first.

Detailed description:

On driver unbind, uart_remove_one_port() is called. Basically it;
  - marks the port dead,
  - calls tty_vhangup(),
  - sets state->uart_port = NULL.

What will happen depends on whether the port is just in use by e.g. getty,
or was also opened as a console.

A. If the tty was not opened as a console:

  - tty_vhangup() will (in __tty_hangup()):
      - mark all file descriptors for this tty hung up by pointing them to
	hung_up_tty_fops,
      - call uart_hangup(), which sets port->count to 0.

  - A subsequent uart_open() (this may be through /dev/ttyS*, or through
    /dev/console if this is a serial console) will fail with -ENXIO as the
    port was marked dead,
  - uart_close() after the failed uart_open() will return early, as
    tty_hung_up_p() (called from tty_port_close_start()) will notice it was
    hung up.

B. If the tty was also opened as a console:

  - tty_vhangup() will (in __tty_hangup()):
      - mark non-console file descriptors for this tty hung up by pointing
	them to hung_up_tty_fops,
      - NOT call uart_hangup(), but instead call uart_close() for every
        non-console file descriptor, so port->count will still have a
	non-zero value afterwards.

  - A subsequent uart_open() will fail with -ENXIO as the port was
    marked dead,
  - uart_close() after the failed uart_open() starts to misbehave:
      - tty_hung_up_p() will not notice it was hung up,
      - As port->count is non-zero, tty_port_close_start() will decrease
        port->count, making the tty and port counts inconsistent. Later,
	warnings like these will be printed:

	    tty_port_close_start: tty->count = 1 port count = 0.

	and
	    tty_port_close_start: count = -1

      - If all of this happens after state->uart_port was set to zero, a
        NULL pointer dereference will happen.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Suggested-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds cond_sched() calls during wait loop to perform
other tasks.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

While reviewing an i2c driver for efm32 that needs a similar property
Wolfram Sang pointed out that "location" is a too generic name for something
that is efm32 specific. So add an appropriate namespace and fall back to the
generic name in case of failure.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

cris allmodconfig:

drivers/tty/serial/max310x.c: In function 'max310x_ioctl':
drivers/tty/serial/max310x.c:885:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
drivers/tty/serial/max310x.c:916:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The hdlcdev_ioctl() code fails to initialize the two padding bytes of
struct sync_serial_settings after the ->loopback member. Add an explicit
memset(0) before filling the structure to avoid the info leak.
Signed-off-by: NSalva Peiró <speiro@ai2.upv.es>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In -RT the spin_lock_irqsave() does not spin but sleep if the lock is
taken. Before that, local_irq_save() is invoked which disables
interrupts even on -RT. Therefore local_irq_save() + spin_lock() does not
work.
In the ->sysrq and oops_in_progress case it is save to trylock the lock
i.e. this is what we do now anyway except for ->sysrq where we assume
that the lock is already taken.

The spin_lock_irqsave() grabs the lock and disables the interrupts on
vanilla (the same behavior) and on -RT it won't disable interrupts.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
[bigeasy: add a patch description]
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>