queue-4.19/alsa-pcm-check-if-ops-are-defined-before-suspending-.patch

   1 From 069b63a147ed5ed28d6d7f88e25bd8a6d45977ca Mon Sep 17 00:00:00 2001
   2 From: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
   3 Date: Fri, 8 Feb 2019 17:29:53 -0600
   4 Subject: ALSA: PCM: check if ops are defined before suspending PCM
   5
   6 [ Upstream commit d9c0b2afe820fa3b3f8258a659daee2cc71ca3ef ]
   7
   8 BE dai links only have internal PCM's and their substream ops may
   9 not be set. Suspending these PCM's will result in their
  10  ops->trigger() being invoked and cause a kernel oops.
  11 So skip suspending PCM's if their ops are NULL.
  12
  13 [ NOTE: this change is required now for following the recent PCM core
  14   change to get rid of snd_pcm_suspend() call.  Since DPCM BE takes
  15   the runtime carried from FE while keeping NULL ops, it can hit this
  16   bug.  See details at:
  17      https://github.com/thesofproject/linux/pull/582
  18   -- tiwai ]
  19
  20 Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
  21 Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
  22 Signed-off-by: Takashi Iwai <tiwai@suse.de>
  23 Signed-off-by: Sasha Levin <sashal@kernel.org>
  24 ---
  25  sound/core/pcm_native.c | 8 ++++++++
  26  1 file changed, 8 insertions(+)
  27
  28 diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
  29 index b67f6fe08a1b..e08c6c6ca029 100644
  30 --- a/sound/core/pcm_native.c
  31 +++ b/sound/core/pcm_native.c
  32 @@ -1513,6 +1513,14 @@ int snd_pcm_suspend_all(struct snd_pcm *pcm)
  33                         /* FIXME: the open/close code should lock this as well */
  34                         if (substream->runtime == NULL)
  35                                 continue;
  36 +
  37 +                       /*
  38 +                        * Skip BE dai link PCM's that are internal and may
  39 +                        * not have their substream ops set.
  40 +                        */
  41 +                       if (!substream->ops)
  42 +                               continue;
  43 +
  44                         err = snd_pcm_suspend(substream);
  45                         if (err < 0 && err != -EBUSY)
  46                                 return err;
  47 --
  48 2.19.1
  49