[alsa-devel] Closing the pcm streams

[Vinod Koul]

On Thu, Feb 18, 2016 at 06:46:04PM +0000, Andy Ng wrote:
> Hello,
> 
> I am working on a system that a DSP provides the audio algorithms and
> in case where the DSP crashes, I would like to shutdown nicely any
> opened PCM streams.
> The DSP has an RPC protocol to the external world. I use a small
> watchdog on ARM to monitor the "health" of the DSP. When the DSP goes
> down, I reset it. However, I would like to close down smoothly the PCM
> streams and inform the user that there was an error while playing.  Is
> there any way to inform the ALSA kernel framework in the kernel that a
> specific PCM stream gone bad? Where is the best point to reset ALSA
> kernel framework?

In your driver...

You can call snd_pcm_stop() on all the streams and then return an error on
commands, usermode may close and restart again

-- 
~Vinod