[alsa-devel] [PATCH 7/8] ALSA: pcm: Add card sync_irq field

[Sridharan, Ranjani]

>
> > >
>> > > I couldn't find anything obvious.  Could you try without changing
>> > > snd_sof_pcm_period_elapsed(), i.e. only adding the stuff and calling
>> > > sync_stop, in order to see whether the additional stuff broke
>> > > anything?
>> > It is indeed the removal of snd_sof_pcm_period_elapsed() that makes the
>> > device hang when the stream is stoppped. But that's a bit surprising
>> > given that all I tried was using the snd_pcm_period_elapsed() directly
>> > instead of scheduling the delayed work to call it.
>>
>> If I read the code correctly, this can't work irrelevantly from the
>> sync_stop stuff.  The call of period_elapsed is from
>> hda_dsp_stream_check() which is performed in bus->reg_lock spinlock in
>> hda_dsp_stream_threaded_handler().  Meanwhile, the XRUN trigger goes
>> to hda_dsp_pcm_trigger() that follows hda_dsp_stream_trigger(), and
>> this function expects the sleepable context due to
>> snd_sof_dsp_read_poll_timeout() call.
>>
>> So something like below works?
>>
>>
>> Takashi
>>
>> --- a/sound/soc/sof/intel/hda-stream.c
>> +++ b/sound/soc/sof/intel/hda-stream.c
>> @@ -592,8 +592,11 @@ static bool hda_dsp_stream_check(struct hdac_bus
>> *bus, u32 status)
>>                                 continue;
>>
>>                         /* Inform ALSA only in case not do that with IPC
>> */
>> -                       if (sof_hda->no_ipc_position)
>> -                               snd_sof_pcm_period_elapsed(s->substream);
>> +                       if (sof_hda->no_ipc_position) {
>> +                               spin_unlock_irq(&bus->reg_lock);
>> +                               snd_pcm_period_elapsed(s->substream);
>> +                               spin_lock_irq(&bus->reg_lock);
>>
> Thanks, Takashi. Yes, I realized it this morning as well that it is due to
> the reg_lock. It does work with this change now. I will run some stress
> tests with this change and get back with the results.
>
Hi Takashi,

Sorry the stress tests took a while.
As we discussed earlier, adding the sync_stop() op didnt quite help the SOF
driver in removing the delayed work for snd_pcm_period_elapsed().

Thanks,
Ranjani

>
> Thanks,
> Ranjani
>