On Sat, 2019-02-09 at 10:27 +0100, Takashi Iwai wrote:
On Sat, 09 Feb 2019 00:29:53 +0100, Pierre-Louis Bossart wrote:
From: Ranjani Sridharan ranjani.sridharan@linux.intel.com
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.
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com
Signed-off-by: Pierre-Louis Bossart < pierre-louis.bossart@linux.intel.com>
sound/core/pcm_native.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 818dff1de545..b6e158ce6650 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -1506,6 +1506,14 @@ 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 andmay
* not have their substream ops set.*/if (!substream->ops)continue;err = snd_pcm_suspend(substream); if (err < 0 && err != -EBUSY) return err;Basically it's OK and safe to apply this check. We may need to add such sanity checks in more places if this really hits.
But I still wonder how this can go through. Is substream->runtime set even if substream->ops is NULL? The substream->runtime is assigned dynamically at opening a substream via snd_pcm_attach_substream(), so without opening it, it must be NULL.
Hi Takashi,
My guess is that this happens during dpcm_be_connect(fe, be, stream) in dpcm_add_paths().
The reason this wasnt exposed before was that the fe dai link pcm's were suspended first. So when it was BE dai links' turn, the pcm was already suspended. In the case of SOF, the order of dai links in the rtd_list is BE dai links first and then the FE dai links.
Thanks, Ranjani
thanks,
Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel