w1: fix oops when w1_search is called from netlink connector

On Sat, Mar 02, 2013 at 10:45:10AM +0100, Sven Geggus wrote:
> This is the bad commit I found doing git bisect:
> 04f482faf50535229a5a5c8d629cf963899f857c is the first bad commit
> commit 04f482faf50535229a5a5c8d629cf963899f857c
> Author: Patrick McHardy <kaber@trash.net>
> Date:   Mon Mar 28 08:39:36 2011 +0000

Good job. I was too lazy to bisect for bad commit;)

Reading the code I found problematic kthread_should_stop call from netlink
connector which causes the oops. After applying a patch, I've been testing
owfs+w1 setup for nearly two days and it seems to work very reliable (no
hangs, no memleaks etc).
More detailed description and possible fix is given below:

Function w1_search can be called from either kthread or netlink callback.
While the former works fine, the latter causes oops due to kthread_should_stop
invocation.

This patch adds a check if w1_search is serving netlink command, skipping
kthread_should_stop invocation if so.

Signed-off-by: Marcin Jurkowski <marcin1j@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Josh Boyer <jwboyer@gmail.com>
Tested-by: Sven Geggus <lists@fuchsschwanzdomain.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org> # 3.0+
Update rtl8192cu driver to 3.4.4_4749
Add IP_VS modules to kernel
defconfig: Add CRYPTO_NULL, CRYPTO_USER, CRYPTO_CRYPTD modules
dwc_otg: fix NAK holdoff and allow on split transactions only

This corrects a bug where if a single active non-periodic endpoint
had at least one transaction in its qh, on frnum == MAX_FRNUM the qh
would get skipped and never get queued again. This would result in
a silent device until error detection (automatic or otherwise) would
either reset the device or flush and requeue the URBs.

Additionally the NAK holdoff was enabled for all transactions - this
would potentially stall a HS endpoint for 1ms if a previous error state
enabled this interrupt and the next response was a NAK. Fix so that
only split transactions get held off.
Merge pull request #279 from P33M/rpi-3.6.y

dwc_otg: fix NAK holdoff and allow on split transactions only
ALSA: bcm2835: show card and subdev creation msg only on debug

On driver probe a message showing that a card and its subdevices
have been created is shown. Probably this message is not needed
unless we have debug enabled on the driver. So, use the driver
audio_info() debug macro instead of just printk().

Also is better to use dev_err() and pr_err() instead KERN_ERR.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
ALSA: bcm2835: use a completion instead of a semaphore for sync

The kernel completion interface is a simple synchronization
mechanism that is preferable over semaphores to signal the
occurence of an event.

Semaphores are optimized for the non-contention case since
in most situations they will be available. But the wait for
completion is the opposite case since the code calling down
will wait on most cases.

So, is better to use the completion mechanism that has been
developed for this exact use case instead of semaphores.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
ALSA: bcm2835: don't use magic numbers on audio start/stop workqueue

The bcm2835 driver uses a workqueue to defer PCM playback start
and stop. Commands are passed to the function as magic numbers
so is more readable to use macro constants.

Also, while being there change the generic name "x" to "cmd"
for the var used to pass the start/stop commands.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
ALSA: bcm2835: defer bcm2835 PCM write using the workqueue

Only PCM playback and stop are deferred using a workqueue on
the ALSA bcm2835 driver. The actual writing of PCM samples
is synchronous.

This works well for the read/write transfer method since
the snd_pcm_ops .copy function pointer runs on process context.

But the snd_pcm_ops .ack function pointer used to implement
direct read/write transfer using a memory-mapped I/O, runs
with interrupts disabled. Since the Kernel to VideoCore
interface driver has to be able to sleep, PCM write has to be
deferred to in preparation to add mmap support to the driver.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
ALSA: bcm2835: add memory-mapped I/O mode for audio stream

ALSA supports two transfers methods for PCM playback: Read/Write
transfer where samples are writtern to the device using standard
read and write functions and Direct Read/Write transfers where
samples can be written directly to a mapped memory area and the
driver is signaled once this has been done.

The bcm2835 driver only supported Read/Write transfer method so
this patch adds mmap support to the driver.

The ARM CPU is not able to directly address the audio device
hardware buffer so audio samples are sent to the device using
a message passing interface (vchiq).

Since hardware buffers can't be directly mapped to user-space
memory, an intermediate buffer (using the PCM indirect API) is
needed to store the audio samples and push them to the device
through videocore.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Merge pull request #286 from martinezjavier/rpi-3.6.y-dev

add mmap support and some cleanups to bcm2835 ALSA driver
Merge remote-tracking branch 'upstream/rpi-3.6.y' into rpi-3.6.y
Update kernel config files