kernel_replicant_linux/sound/core, branch v4.4-rc7

ALSA: Constify ratden/ratnum constraints

2015-10-28T10:42:22+00:00

The ALSA core does not modify the constraints provided by a driver. Most
constraint helper functions already take a const pointer to the constraint
description, the exception at the moment being the ratden and ratnum
constraints. Make those const as well, this allows a driver to declare them
as const.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Takashi Iwai

ALSA: Remove transfer_ack_{begin,end} callbacks from struct snd_pcm_runtime

2015-10-22T15:16:23+00:00

While there is nothing wrong with the transfer_ack_begin and
transfer_ack_end callbacks per-se, the last documented user was part of the
alsa-driver 0.5.12a package, which was released 14 years ago and even
predates the upstream integration of the ALSA core and has subsequently
been superseded by newer alsa-driver releases.

This seems to indicate that there is no need for having these callbacks and
they are just cruft that can be removed.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Takashi Iwai

ALSA: timer: add config item to export PCM timer disabling for expert

2015-10-16T12:31:38+00:00

PCM timer is not always used. For embedded device, we need an interface
to disable it when it is not needed, to shrink the kernel size and
memory footprint, here add CONFIG_SND_PCM_TIMER for it.

When both CONFIG_SND_PCM_TIMER and CONFIG_SND_TIMER is unselected,
about 25KB saving bonus we can get.

Please be noted that when disabled, those stubs who using pcm timer
(e.g. dmix, dsnoop & co) may work incorrectlly.

Suggested-by: Takashi Iwai 
Signed-off-by: Jie Yang 
Signed-off-by: Takashi Iwai

ALSA: oss: underflow in snd_mixer_oss_proc_write()

2015-10-15T08:00:29+00:00

We cap the upper bound of "idx" but not the negative side.  Let's make
it unsigned to fix this.

Signed-off-by: Dan Carpenter 
Signed-off-by: Takashi Iwai

ALSA: seq_oss: fix waitqueue_active without memory barrier in snd-seq-oss

2015-10-09T07:45:52+00:00

snd_seq_oss_readq_put_event() seems to be missing a memory barrier which
might cause the waker to not notice the waiter and miss sending a
wake_up as in the following figure.

    snd_seq_oss_readq_put_event		    snd_seq_oss_readq_wait
------------------------------------------------------------------------
					/* wait_event_interruptible_timeout */
					 /* __wait_event_interruptible_timeout */
					  /* ___wait_event */
					  for (;;) {									 prepare_to_wait_event(&wq, &__wait,
					    state);
spin_lock_irqsave(&q->lock, flags);
if (waitqueue_active(&q->midi_sleep))
/* The CPU might reorder the test for
   the waitqueue up here, before
   prior writes complete */
					  if ((q->qlen>0 || q->head==q->tail)
					  ...
					  __ret = schedule_timeout(__ret)
if (q->qlen >= q->maxlen - 1) {
memcpy(&q->q[q->tail], ev, sizeof(*ev));
q->tail = (q->tail + 1) % q->maxlen;
q->qlen++;
------------------------------------------------------------------------

There are two other place in sound/core/seq/oss/ which have similar
code.  The attached patch removes the call to waitqueue_active() leaving
just wake_up() behind.  This fixes the problem because the call to
spin_lock_irqsave() in wake_up() will be an ACQUIRE operation.

I found this issue when I was looking through the linux source code
for places calling waitqueue_active() before wake_up*(), but without
preceding memory barriers, after sending a patch to fix a similar
issue in drivers/tty/n_tty.c  (Details about the original issue can be
found here: https://lkml.org/lkml/2015/9/28/849).

Signed-off-by: Kosuke Tatsukawa 
Signed-off-by: Takashi Iwai

ALSA: pcm: Avoid double hw_free calls at releasing a stream

2015-09-29T10:57:42+00:00

snd_pcm_release_substream() always calls hw_free op when the stream
was opened.  This is superfluous in most cases because it's been
already released via explicit hw_free ioctl.  Although this double
call is usually OK as this callback should be written to be called
multiple times, it's better to avoid superfluous calls.

Reported-by: Vinod Koul 
Tested-by: Jeeja Kp 
Signed-off-by: Takashi Iwai

ALSA: core: check for underflow in snd_pcm_sw_params()

2015-09-24T09:46:25+00:00

As far as I can see, having an invalid ->tstamp_mode is harmless, but
adding a check silences a static checker warning.

Signed-off-by: Dan Carpenter 
Signed-off-by: Takashi Iwai

ALSA: pcm: remove structure member of 'struct snd_pcm_hwptr_log *' type because this structure had been removed

2015-09-13T10:03:15+00:00

This structure was added by 4d96eb255c53 ('ALSA: pcm_lib - add possibility
to log last 10 DMA ring buffer positions') to store PCM pointers
information of latest 10 pointer movements (=XRUN_LOG_CNT). When
CONFIG_SND_PCM_XRUN_DEBUG is configured, 'struct snd_pcm_runtime' has
'hwptr_log' member with a pointer to the structure. When calling
xrun_log() in pcm_lib.c, the structure was allocated to the pointer.
When calling snd_pcm_detach_substream() in pcm.c, the allocated pointer
is released.

In f5914908a5b7 ('ALSA: pcm: Replace PCM hwptr tracking with tracepoints'),
the pointer logging is replaced with using Linux Kernel Tracepoints. The
structure was also removed, while it's just declared. The member and kfree
still remains.

This commit removes the member and related codes. I think this was
overlooked because it brings no errors/warnings to C compilers.

Fixes: f5914908a5b7 ('ALSA: pcm: Replace PCM hwptr tracking with tracepoints')
Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

Merge tag 'asoc-fix-v4.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

2015-07-24T18:08:13+00:00

ASoC: Fixes for v4.2

A lot of small fixes here, a few to the core:

 - Fix for binding DAPM stream widgets on devices with prefixes assigned
   to them
 - Minor fixes for the newly added topology interfaces
 - Locking and memory leak fixes for DAPM
 - Driver specific fixes

ALSA: pcm: Fix lockdep warning with nonatomic PCM ops

2015-07-17T13:36:54+00:00

With the nonatomic PCM ops, the system may spew lockdep warnings like:

 =============================================
 [ INFO: possible recursive locking detected ]
 4.2.0-rc1-jeejaval3 #12 Not tainted
 ---------------------------------------------
 aplay/4029 is trying to acquire lock:
  (snd_pcm_link_rwsem){.+.+.+}, at: [] snd_pcm_stream_lock+0x43/0x60

 but task is already holding lock:
  (snd_pcm_link_rwsem){.+.+.+}, at: [] snd_pcm_action_nonatomic+0x29/0x80

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(snd_pcm_link_rwsem);
   lock(snd_pcm_link_rwsem);

Although this is false-positive as the rwsem is taken always as
read-only for these code paths, it's certainly annoying to see this at
any occasion.  A simple fix is to use down_read_nested() in
snd_pcm_stream_lock() that can be called inside another lock.

Reported-by: Vinod Koul 
Reported-by: Jeeja Kp 
Tested-by: Jeeja Kp 
Cc: 
Signed-off-by: Takashi Iwai