[alsa-devel] Question about device recovery when under/over run error case

[Kuninori Morimoto]

Hi Sakamoto-san

> >> The 'lock' is what I mentioned in former message to you:
> >>
> >> [alsa-devel] Can I stop sound from driver as system error ?
> >> http://mailman.alsa-project.org/pipermail/alsa-devel/2015-December/102010.html
> >
> > Yes, I had asked same question to ML, I'm sorry about that.
> > And, can I confirm about your concern ?
> > I guess you are worrying about dead-lock by stop xrun, but is that correct ?
> 
> Recent SoC tends to accumurate much IPs with variety functionalities.
> 
> If your SoC, R-Car, has such IPs and snd-soc-rcar utilize it, I can
> assume that snd-soc-rcar require to wait for some events after
> operating to the IPs. Or snd-soc-rcar require to manage race
> conditions between many PCM substreams.
> 
> In this case, current structure of snd-soc-rcar may cause problems (at
> least, in the end of last year), because it pushes many operations
> into 'struct snd_pcm_ops.trigger'. This callback is executed in both
> of process context and interrupt context and drivers should not wait
> for events or should not manage race conditions.

Thank you for explaining detail of your concern.
I believe snd-soc-rcar is OK at this point, but of course not sure in the future.
I will keep considering your advice, and fix any problems step-by-step.
Thanks again