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>
/* 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;