On Fri, 13 Oct 2017 11:11:42 +0200,
Kuninori Morimoto wrote:
>
>
> Hi Takashi
>
> > > I tested this patch-set.
> > > I noticed that it doesn't work if I used DPCM
> > > (Kernel has Oops).
> > > I will investigate it next week
> >
> > Could you show the Oops message if you have?
> > My concern is whether it happens by stopping at disconnect, or it's
> > just another missing piece.
>
> OK, but kernel log doesn't help you.
> see below
>
> My environment now is I'm using DPCM.
> FE : rsnd
> FE : rsnd
> BE : ak4613
>
> 1st issue is that kernel need below patch.
> I guess BE is using dummy driver, and it doesn't have ops(?).
> If this is needed, I can post it.
No, this can't be right. Every PCM implementation mandates the
presence of a trigger callback. It's a must. If a fix needed, it has
to be fixed in the driver side.
> -----------------------
> diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
> index 2fec2fe..972408b 100644
> --- a/sound/core/pcm_native.c
> +++ b/sound/core/pcm_native.c
> @@ -1241,7 +1241,8 @@ static int snd_pcm_do_stop(struct snd_pcm_substream *substream, int state)
> {
> if (substream->runtime->trigger_master == substream &&
> snd_pcm_running(substream))
> - substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
> + if (substream->ops && substream->ops->trigger)
> + substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_STOP);
> return 0; /* unconditonally stop all substreams */
> }
> -----------------------
> After this patch, my driver side clock counter mismatch Oops happen.
> It seems this is because FE side wasn't called snd_pcm_stop();
> (= BE side only called snd_pcm_stop()).
So the check might work around an Oops, but it's no "fix", per se.
> I could confirm this by printing who's stop was called by local quick hack.
>
> Maybe timing reason, if kernel has Oops for some reasons,
> then, both BE/FE snd_pcm_stop() are called.
> If no Oops, BE snd_pcm_stop() only called.
Any pending delayed work (like rtd->delayed_work)?
This is flushed at soc_cleanup_card_resources(), but it's called at
card removal, thus it's too late for the hot-removal of the
component.
thanks,
Takashi
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