Commit ccce7643 authored Feb 08, 2019 by Ranjani Sridharan Committed by Greg Kroah-Hartman Apr 05, 2019

ALSA: PCM: check if ops are defined before suspending PCM

[ Upstream commit d9c0b2afe820fa3b3f8258a659daee2cc71ca3ef ]

BE dai links only have internal PCM's and their substream ops may
not be set. Suspending these PCM's will result in their
 ops->trigger() being invoked and cause a kernel oops.
So skip suspending PCM's if their ops are NULL.

[ NOTE: this change is required now for following the recent PCM core
  change to get rid of snd_pcm_suspend() call.  Since DPCM BE takes
  the runtime carried from FE while keeping NULL ops, it can hit this
  bug.  See details at:
     https://github.com/thesofproject/linux/pull/582


  -- tiwai ]

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent d21a63fc

sound/core/pcm_native.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -1513,6 +1513,14 @@ int snd_pcm_suspend_all(struct snd_pcm *pcm)
		/* FIXME: the open/close code should lock this as well */
		if (substream->runtime == NULL)
		continue;

		/*
		* Skip BE dai link PCM's that are internal and may
		* not have their substream ops set.
		*/
		if (!substream->ops)
		continue;

		err = snd_pcm_suspend(substream);
		if (err < 0 && err != -EBUSY)
		return err;