Commit Graph

2333 Commits

Author SHA1 Message Date
Geert Uytterhoeven
4ed94cd440 serial_core: Avoid NULL pointer dereference in uart_close()
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: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:17:55 -07:00
Geert Uytterhoeven
4c6d5b4d53 serial_core: Get a reference for port->tty in uart_remove_one_port()
Suggested-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:16:59 -07:00
Alexander Shiyan
63e3ad3252 serial: clps711x: Give a chance to perform useful tasks during wait loop
This patch adds cond_sched() calls during wait loop to perform
other tasks.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:13:24 -07:00
Geert Uytterhoeven
015355b70e serial_core: Grammar s/ports/port's/
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:13:23 -07:00
Geert Uytterhoeven
02088ca63b serial_core: Spelling s/contro/control/
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:13:23 -07:00
Uwe Kleine-König
74be65a3cf serial: efm32: properly namespace location property
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: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:13:23 -07:00
Geert Uytterhoeven
58dea3577c serial: max310x: Add missing #include <linux/uaccess.h>
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: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:13:23 -07:00
Salva Peiró
b19a47e060 synclink: fix info leak in ioctl
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: Salva Peiró <speiro@ai2.upv.es>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:13:23 -07:00
Ingo Molnar
ebade5e833 serial: 8250: Clean up the locking for -rt
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: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: add a patch description]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-08 22:24:53 -08:00
Aaron Sierra
41d3f09913 serial: 8250_pci: change BayTrail default uartclk
The Intel BayTrail HSUART power-on default reference clock is 44.2368 MHz,
but 73.728 MHz provides 0% error for additional "conventional" baud rates
above 460800 (e.g. 576000, 921600, and 1152000).

Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-08 22:24:53 -08:00
Aaron Sierra
50825c57ab serial: 8250_pci: more BayTrail error-free bauds
Support the following additional baud rates with 0% error:
	500000, 1500000, 2500000, 3500000

Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-08 22:24:53 -08:00
Geert Uytterhoeven
bf13c9a894 serial: sh-sci: Add missing call to uart_remove_one_port() in failure path
If cpufreq_register_notifier() fails, we have to remove the port added by
sci_probe_single(), which is not done by sci_cleanup_single().

Else the serial port stays active from the point of view of the serial
subsystem, and it may crash when userspace getty is started, or when the
loadable driver module is unloaded.

This was introduced by commit 6dae14216c
("serial: sh-sci: Fix probe error paths").

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:39:38 -08:00
Geert Uytterhoeven
5f5c9ae56c serial_core: Unregister console in uart_remove_one_port()
If the serial port being removed is used as a console, it must also be
unregistered from the console subsystem using unregister_console().

uart_ops.release_port() will release resources (e.g. iounmap() the serial
port registers), causing a crash on subsequent kernel output if the console
is still registered.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:39:38 -08:00
Richard Genoud
a3c1fa99f4 tty/serial: at91: remove unused open/close hooks
commit 95e629b761 removed the use of board
specific hooks in serial_at91.h, so now, the open/close hook are just
dead code.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:38:39 -08:00
Richard Genoud
ddaa603739 tty/serial: at91: use dev_err instead of printk
For better consistency.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:38:39 -08:00
Hannes Reinecke
723abd87f6 tty: Set correct tty name in 'active' sysfs attribute
The 'active' sysfs attribute should refer to the currently active tty
devices the console is running on, not the currently active console. The
console structure doesn't refer to any device in sysfs, only the tty the
console is running on has. So we need to print out the tty names in
'active', not the console names.

There is one special-case, which is tty0. If the console is directed to
it, we want 'tty0' to show up in the file, so user-space knows that the
messages get forwarded to the active VT. The ->device() callback would
resolve tty0, though. Hence, treat it special and don't call into the VT
layer to resolve it (plymouth is known to depend on it).

Cc: Lennart Poettering <lennart@poettering.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Werner Fink <werner@suse.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:36:46 -08:00
Alexander Shiyan
45af780a0f serial: imx: Remove init() and exit() platform callbacks
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:36:45 -08:00
Alexander Shiyan
436e4ab5fc serial: imx: Use dev_name() for request_irq() to distinguish UARTs
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:36:45 -08:00
Alexander Shiyan
da82f99724 serial: imx: Use devm_ioremap_resource()
Use devm_ioremap_resource() in order to make the code simpler and
it gives proper codes on errors.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:36:45 -08:00
Peter Hurley
a9c3f68f3c tty: Fix low_latency BUG
The user-settable knob, low_latency, has been the source of
several BUG reports which stem from flush_to_ldisc() running
in interrupt context. Since 3.12, which added several sleeping
locks (termios_rwsem and buf->lock) to the input processing path,
the frequency of these BUG reports has increased.

Note that changes in 3.12 did not introduce this regression;
sleeping locks were first added to the input processing path
with the removal of the BKL from N_TTY in commit
a88a69c912,
'n_tty: Fix loss of echoed characters and remove bkl from n_tty'
and later in commit 38db89799b,
'tty: throttling race fix'. Since those changes, executing
flush_to_ldisc() in interrupt_context (ie, low_latency set), is unsafe.

However, since most devices do not validate if the low_latency
setting is appropriate for the context (process or interrupt) in
which they receive data, some reports are due to misconfiguration.
Further, serial dma devices for which dma fails, resort to
interrupt receiving as a backup without resetting low_latency.

Historically, low_latency was used to force wake-up the reading
process rather than wait for the next scheduler tick. The
effect was to trim multiple milliseconds of latency from
when the process would receive new data.

Recent tests [1] have shown that the reading process now receives
data with only 10's of microseconds latency without low_latency set.

Remove the low_latency rx steering from tty_flip_buffer_push();
however, leave the knob as an optional hint to drivers that can
tune their rx fifos and such like. Cleanup stale code comments
regarding low_latency.

[1] https://lkml.org/lkml/2014/2/20/434

"Yay.. thats an annoying historical pain in the butt gone."
	-- Alan Cox

Reported-by: Beat Bolli <bbolli@ewanet.ch>
Reported-by: Pavel Roskin <proski@gnu.org>
Acked-by: David Sterba <dsterba@suse.cz>
Cc: Grant Edwards <grant.b.edwards@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Hal Murray <murray+fedora@ip-64-139-1-69.sjc.megapath.net>
Cc: <stable@vger.kernel.org> # 3.12.x+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:31:00 -08:00
Florian Fainelli
9277285f98 tty: serial: bcm63xx_uart: add support for DT probing
Add a matching table for the the bcm63xx_uart driver on the compatible
string "brcm,bcm6345-uart" which covers all BCM63xx implementations and
reflects the fact that this block was first introduced with the BCM6345
SoC.  Also make sure that we convert the id based on the uart aliases
provided by the relevant Device Tree.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:27:18 -08:00
Florian Fainelli
5811712ffb tty: serial: bcm63xx_uart: define UART_REG_SIZE constant
The bcm63xx_uart driver uses RSET_UART_SIZE which is a constant defined
for MIPS-based BCM63xx platforms, pull this constant value from the
MIPS-specific header and put it in include/linux/serial_bcm63xx.h to
make the driver platform agnostic.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:27:18 -08:00
Florian Fainelli
f04430cead tty: serial: bcm63xx_uart: include linux/io.h
Include linux/io.h which provides the definition for
__raw_{readl,writel}, this is not necessary on MIPS since there is an
implicit inclusion, but it is on ARM for instance.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:27:17 -08:00
Adam Borowski
63f3a16db9 vt: detect and ignore OSC codes.
These can be used to send commands consisting of an arbitrary string to the
terminal, most often used to set a terminal's window title or to redefine
the colour palette.  Our console doesn't use OSC, unlike everything else,
which can lead to junk being displayed if a process sends such a code
unconditionally.

The rules for termination follow established practice rather than Ecma-48.
Ecma-48 requires the string to use only byte values 0x08..0x0D and
0x20..0x7E, terminated with either ESC \ or 0x9C.  This would disallow using
8-bit characters, which are reasonable for example in window titles.
A widespread idiom is to terminate with 0x07.  The behaviour for other
control characters differs between terminal emulators, I followed libvte and
xterm:
* 0x07 and ESC anything terminate
* nothing else terminates, all 8-bit values including 0x9C are considered a
  part of the string

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:25:47 -08:00
Adam Borowski
b290af68de vt: drop an useless enum and assignment.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:25:47 -08:00
Paul Gortmaker
bd2fe272a8 drivers/tty/serial: deal with 8250_core.c uninitialized warning for good
Every couple of months, someone sends a patch to fix:

drivers/tty/serial/8250/8250_core.c: In function 'serial_unlink_irq_chain':
drivers/tty/serial/8250/8250_core.c:1712:2: warning: 'i' may be used uninitialized in this function [-Wuninitialized]

and they in turn get a NACK for their efforts, and are told that
their compiler is broken.  This has been going on since at least
the year 2008:  https://lkml.org/lkml/2008/11/24/433

Lets add a comment, so that subsequent patches don't get as far as
the maintainers or the mailing lists.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:25:47 -08:00
Greg Kroah-Hartman
8301bb240d Merge 3.14-rc4 into tty-next
We want the tty revert here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-24 15:56:45 -08:00
Greg Kroah-Hartman
5c0a2450d6 Revert "tty: Set correct tty name in 'active' sysfs attribute"
This reverts commit d8a5dc3033.

This breaks plymouth installs, either because plymouth is using the file
"incorrectly" or because the patch is incorrect.  Either way, this needs
to be reverted until it is all figured out.

Reported-by: Josh Boyer <jwboyer@fedoraproject.org>
Reported-by: Ray Strode <halfline@gmail.com>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Werner Fink <werner@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-22 14:31:04 -08:00
Yuan Yao
f1cd8c8792 serial: fsl_lpuart: add DMA support
Add dma support for lpuart. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.

Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-18 12:50:26 -08:00
Greg Kroah-Hartman
51d52b26e1 Merge 3.14-rc3 into tty-next
This is for the fixes in that release, we want them here too.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-18 09:09:09 -08:00
Alexander Shiyan
0fd927f578 serial: max310x: Fix sparse warnings
sparse warnings: (new ones prefixed by >>)

>> drivers/tty/serial/max310x.c:906:45: sparse: incorrect type in argument 2 (different address spaces)
 drivers/tty/serial/max310x.c:906:45: expected void const [noderef] <asn:1>*from
 drivers/tty/serial/max310x.c:906:45: got struct serial_rs485 *<noident>
>> drivers/tty/serial/max310x.c:938:35: sparse: incorrect type in argument 1 (different address spaces)
 drivers/tty/serial/max310x.c:938:35: expected void [noderef] <asn:1>*to
 drivers/tty/serial/max310x.c:938:35: got struct serial_rs485 *<noident>

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-15 12:16:21 -08:00
Paul Bolle
b2b2d6067d tty: serial: crisv10: Drop remaining code for CRISv10 CPU simulator
The Kconfig symbol SVINTO_SIM got dropped in commit e269a86941 ("Drop
code for CRISv10 CPU simulator"). Now drop the remaining code for that
simulator.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-15 12:16:21 -08:00
Alexander Shiyan
86a41c46c7 serial: max310x: Fix build error
This is a temporary solution to fix following issue:
config: make ARCH=alpha allyesconfig

All error/warnings:

 drivers/tty/serial/max310x.c: In function 'max310x_ioctl':
>> drivers/tty/serial/max310x.c:905:7: error: 'TIOCSRS485' undeclared (first use in this function)
 drivers/tty/serial/max310x.c:905:7: note: each undeclared identifier is reported only once for each function it appears in
>> drivers/tty/serial/max310x.c:906:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
>> drivers/tty/serial/max310x.c:929:7: error: 'TIOCGRS485' undeclared (first use in this function)
>> drivers/tty/serial/max310x.c:938:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
 cc1: some warnings being treated as errors

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 15:20:13 -08:00
Greg Kroah-Hartman
1456dad9bc Revert "serial: max310x: Fix build error"
This reverts commit e3c6ea9b1b as it
didn't help anything, and caused more problems than expected.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 15:18:57 -08:00
Petr Písař
0930b0950a vt: Fix secure clear screen
\E[3J console code (secure clear screen) needs to update_screen(vc)
in order to write-through blanks into off-screen video memory.

This has been removed accidentally in 3.6 by:

commit 81732c3b2f
Author: Jean-François Moine <moinejf@free.fr>
Date:   Thu Sep 6 19:24:13 2012 +0200

    tty vt: Fix line garbage in virtual console on command line edition

Signed-off-by: Petr Písař <petr.pisar@atlas.cz>
Cc: stable <stable@vger.kernel.org> # 3.6
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 11:12:00 -08:00
Paul Gortmaker
f76a1cbed1 hvc: ensure hvc_init is only ever called once in hvc_console.c
Commit 3e6c6f630a ("Delay creation of
khcvd thread") moved the call of hvc_init from being a device_initcall
into hvc_alloc, and used a non-null hvc_driver as indication of whether
hvc_init had already been called.

The problem with this is that hvc_driver is only assigned a value
at the bottom of hvc_init, and so there is a window where multiple
hvc_alloc calls can be in progress at the same time and hence try
and call hvc_init multiple times.  Previously the use of device_init
guaranteed that hvc_init was only called once.

This manifests itself as sporadic instances of two hvc_init calls
racing each other, and with the loser of the race getting -EBUSY
from tty_register_driver() and hence that virtual console fails:

    Couldn't register hvc console driver
    virtio-ports vport0p1: error -16 allocating hvc for port

Here we add an atomic_t to guarantee we'll never run hvc_init twice.

Cc: stable@vger.kernel.org  # v2.6.24+
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: 3e6c6f630a ("Delay creation of khcvd thread")
Reported-by: Jim Somerville <Jim.Somerville@windriver.com>
Tested-by: Jim Somerville <Jim.Somerville@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:41:47 -08:00
Qipan Li
9be16b38cf serial: sirf: move to use generic dma dt-binding to get dma channels
instead of using sirf specific dma channel property like "sirf,uart-dma-rx-channel"
and "sirf,uart-dma-tx-channel", here we move to use generic dma dt-binding to get
the channel like:
- sirf,uart-dma-rx-channel = <21>;
- sirf,uart-dma-tx-channel = <2>;
+ dmas = <&dmac1 5>, <&dmac0 2>;
+ dma-names = "rx", "tx";

and we move dma_request_channel() to dma_request_slave_channel(), we don't need to
call sirfsoc dma filter function sirfsoc_dma_filter_id() again.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:36:25 -08:00
Tushar Behera
ef2889f7ff serial: pl011: Move uart_register_driver call to device probe
uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically happen
during device probe call.

In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with same default major/minor numbers are
included in the kernel.

A typical case is observed with amba-pl011 and samsung-uart drivers.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:33:00 -08:00
Tushar Behera
6f134c3c77 serial: samsung: Move uart_register_driver call to device probe
uart_register_driver call binds the driver to a specific device
node through tty_register_driver call. This should typically happen
during device probe call.

In a multiplatform scenario, it is possible that multiple serial
drivers are part of the kernel. Currently the driver registration fails
if multiple serial drivers with same default major/minor numbers are
included in the kernel.

A typical case is observed with amba-pl011 and samsung-uart drivers.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:32:59 -08:00
Alexander Shiyan
d4f6b412ec serial: max310x: Fix build warning
config: x86_64-randconfig-x006 (attached as .config)

All warnings:

 drivers/tty/serial/max310x.c: In function 'max310x_probe':
>> drivers/tty/serial/max310x.c:1240:1: warning: label 'out_uart' defined but not used [-Wunused-label]

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:18:49 -08:00
Alexander Shiyan
e3c6ea9b1b serial: max310x: Fix build error
config: make ARCH=alpha allyesconfig

All error/warnings:

 drivers/tty/serial/max310x.c: In function 'max310x_ioctl':
>> drivers/tty/serial/max310x.c:905:7: error: 'TIOCSRS485' undeclared (first use in this function)
 drivers/tty/serial/max310x.c:905:7: note: each undeclared identifier is reported only once for each function it appears in
>> drivers/tty/serial/max310x.c:906:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
>> drivers/tty/serial/max310x.c:929:7: error: 'TIOCGRS485' undeclared (first use in this function)
>> drivers/tty/serial/max310x.c:938:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
 cc1: some warnings being treated as errors

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:18:49 -08:00
Huang Shijie
2ad28e3efe serial: imx: always wake up the processes in the TX callback
The current code only wakes up the processes when the circle
buffer has less data then the WAKEUP_CHARS.

But sometimes, the circle buffer may has data more then the WAKEUP_CHARS,
in such case, the processes will hang.

This patch makes it always wakes up the processes in the TX callback.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:18:48 -08:00
Nicolas Ferre
c972d806fd tty/serial: atmel_serial: remove dev_dbg in atmel_set_termios
This fixes a driver bug which stopped the whole system (in case
of serial console).
This log message is not useful anyway as this information is
printed elsewhere.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:18:48 -08:00
Peter Hurley
25e8d0ed75 n_tty: Simplify input_available_p()
Greg,

Please note this patch requires
   n_tty: Fix poll() when TIME_CHAR and MIN_CHAR == 0

Regards,
Peter Hurley

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:18:48 -08:00
Greg Kroah-Hartman
5669b70502 Merge branch 'tty-linus' into tty-next
We want the tty core fixes in here as well, because other patches depend
on them.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:06:34 -08:00
Joe Schultz
45a7bd6359 serial: 8250: Support XR17V35x fraction divisor
The Exar XR17V35x family of UARTs have an additional fractional divisor
register (DLD) which was not being used. Calculate and set this
register for these devices to reduce their baud rate error.

Signed-off-by: Joe Schultz <jschultz@xes-inc.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:02:19 -08:00
Peter Hurley
e2613be509 n_tty: Fix stale echo output
When echoes cannot be flushed to output (usually because the tty
has no more write room) and L_ECHO is subsequently turned off, then
when L_ECHO is turned back on, stale echoes are output.

Output completed echoes regardless of the L_ECHO setting:
  1. before normal writes to that tty
  2. if the tty was stopped by soft flow control and is being
     restarted

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: <stable@vger.kernel.org> # 3.13.x
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:02:19 -08:00
Qipan Li
fb78b81142 serial: sirf: fix kernel panic caused by unpaired spinlock
commit 8b9ade9f74 coming from Viresh Kumar "tty: serial: sirfsoc: drop
uart_port->lock before calling tty_flip_buffer_push()" broke sirfsoc uart
driver by knic:

	[    5.129122] BUG: spinlock already unlocked on CPU#0, ip6tables/1331
	[    5.132554]  lock: sirfsoc_uart_ports+0x4/0x8a0, .magic: dead4ead,
	.owner: <none>/-1, .owner_cpu: -1
	[    5.141651] CPU: 0 PID: 1331 Comm: ip6tables Tainted: G
	W  O 3.10.16 #3
	[    5.148866] [<c0013528>] (unwind_backtrace+0x0/0xe0) from
	[<c0010e70>] (show_stack+0x10/0x14)
	[    5.157362] [<c0010e70>] (show_stack+0x10/0x14) from
	[<c01a5e68>] (do_raw_spin_unlock+0x40/0xc8)
	[    5.166125] [<c01a5e68>] (do_raw_spin_unlock+0x40/0xc8) from
	[<c03ff8b4>] (_raw_spin_unlock+0x8/0x40)
	[    5.175322] [<c03ff8b4>] (_raw_spin_unlock+0x8/0x40) from
	[<c0203fcc>] (sirfsoc_uart_pio_rx_chars+0xa4/0xc0)
	[    5.185120] [<c0203fcc>]
	(sirfsoc_uart_pio_rx_chars+0xa4/0xc0) from [<c0204fb8>]
	(sirfsoc_rx_tmo_process_tl+0xdc/0x1e0)
	[    5.195875] [<c0204fb8>]
	(sirfsoc_rx_tmo_process_tl+0xdc/0x1e0) from [<c0024b50>]
	(tasklet_action+0x8c/0xec)
	[    5.205673] [<c0024b50>] (tasklet_action+0x8c/0xec) from
	[<c00242a8>] (__do_softirq+0xec/0x1d4)
	[    5.214347] [<c00242a8>] (__do_softirq+0xec/0x1d4) from
	[<c0024428>] (do_softirq+0x48/0x54)
	[    5.222674] [<c0024428>] (do_softirq+0x48/0x54) from
	[<c0024690>] (irq_exit+0x74/0xc0)
	[    5.230573] [<c0024690>] (irq_exit+0x74/0xc0) from
	[<c000e1e8>] (handle_IRQ+0x6c/0x90)
	[    5.238465] [<c000e1e8>] (handle_IRQ+0x6c/0x90) from
	[<c000d500>] (__irq_svc+0x40/0x70)
	[    5.246446] [<c000d500>] (__irq_svc+0x40/0x70) from
	[<c0092e7c>] (mark_page_accessed+0xc/0x68)
	[    5.255034] [<c0092e7c>] (mark_page_accessed+0xc/0x68) from
	[<c00a2a4c>] (unmap_single_vma+0x3bc/0x550)
	[    5.264402] [<c00a2a4c>] (unmap_single_vma+0x3bc/0x550) from
	[<c00a3b4c>] (unmap_vmas+0x44/0x54)
	[    5.273164] [<c00a3b4c>] (unmap_vmas+0x44/0x54) from
	[<c00a81a8>] (exit_mmap+0xc4/0x1e0)
	[    5.281233] [<c00a81a8>] (exit_mmap+0xc4/0x1e0) from
	[<c001bb78>] (mmput+0x3c/0xdc)
	[    5.288868] [<c001bb78>] (mmput+0x3c/0xdc) from [<c0021b0c>]
	(do_exit+0x30c/0x828)
	[    5.296413] [<c0021b0c>] (do_exit+0x30c/0x828) from
	[<c0022dac>] (do_group_exit+0x4c/0xb0)
	[    5.304653] [<c0022dac>] (do_group_exit+0x4c/0xb0) from
	[<c0022e20>] (__wake_up_parent+0x0/0x18)

Root cause:
the commit dropped uart_port->lock before calling tty_flip_buffer_push(), but in sirfsoc-uart,
sirfsoc_uart_pio_rx_chars() can be called by sirfsoc_rx_tmo_process_tl(). here uart_port->lock
has not been taken yet. so that caused unpaired lock/unlock.

Solution:
This patch is doing a quick fix for that, it adds spin_lock/unlock(&port->lock) protect to
sirfsoc_uart_pio_rx_chars() in sirfsoc_rx_tmo_process_tl() to keep spin_lock/unlock in pair.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: stable <stable@vger.kernel.org> # 3.12
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 10:02:19 -08:00
Dmitry Eremin-Solenikov
333c085e4b serial: 8250_pci: unbreak last serial ports on NetMos 9865 cards
Aparently 9865 uses standard BAR encoding scheme (unlike 99xx cards).
Current pci_netmos_9900_setup() uses wrong BAR indices for the 9865 PCI
device, function 2. Using standard BAR indices makes all 6 ports work
for me. Thus disable the NetMos 9900 quirk for NetMos 9865 pci device.

For the reference, here is the relevant part of lspci for my device:

02:07.0 Serial controller: MosChip Semiconductor Technology Ltd. PCI
9865 Multi-I/O Controller (prog-if 02 [16550])
	Subsystem: Device a000:1000
	Flags: bus master, medium devsel, latency 32, IRQ 17
	I/O ports at ac00 [size=8]
	Memory at fcfff000 (32-bit, non-prefetchable) [size=4K]
	Memory at fcffe000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [48] Power Management version 2
	Kernel driver in use: serial

02:07.1 Serial controller: MosChip Semiconductor Technology Ltd. PCI
9865 Multi-I/O Controller (prog-if 02 [16550])
	Subsystem: Device a000:1000
	Flags: bus master, medium devsel, latency 32, IRQ 18
	I/O ports at a800 [size=8]
	Memory at fcffd000 (32-bit, non-prefetchable) [size=4K]
	Memory at fcffc000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [48] Power Management version 2
	Kernel driver in use: serial

02:07.2 Communication controller: MosChip Semiconductor Technology Ltd.
PCI 9865 Multi-I/O Controller
	Subsystem: Device a000:3004
	Flags: bus master, medium devsel, latency 32, IRQ 19
	I/O ports at a400 [size=8]
	I/O ports at a000 [size=8]
	I/O ports at 9c00 [size=8]
	I/O ports at 9800 [size=8]
	Memory at fcffb000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [48] Power Management version 2
	Kernel driver in use: serial

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 09:57:33 -08:00
Peter Hurley
a5934804a8 n_tty: Fix poll() when TIME_CHAR and MIN_CHAR == 0
Commit eafbe67f84,
  n_tty: Refactor input_available_p() by call site
broke poll() when TIME_CHAR(tty) and MIN_CHAR(tty) are both 0.

When TIME_CHAR and MIN_CHAR are both 0, input is available if the
read_cnt is 1 (not 0).

Reported-by: Eric Dumazet <edumazet@google.com>
Tested-by: Eric Dumazet <edumazet@google.com>
Reported-by: Stephane Eranian <eranian@google.com>
Tested-by: David Ahern <dsahern@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 09:57:33 -08:00