Hi Mark,

On Tue, Mar 10, 2020 at 12:45:44PM +0000, Mark Brown wrote:

On Mon, Mar 09, 2020 at 06:07:48PM +0100, Guennadi Liakhovetski wrote:

...

soc_dpcm_runtime_update() to activate an audio path and update audio routing. When streaming is stopped, the vhost driver calls soc_dpcm_runtime_update() and snd_soc_runtime_deactivate(). The latter doesn't work at the moment, because the DPCM doesn't recognise the path as inactive. We address this by adding a "mode" parameter to soc_dpcm_runtime_update(). If virtualisation isn't used, the current behaviour isn't affected.

So why doesn't DPCM recognize that the path is inactive and why is it better to do this than fix whatever the issue is there?

Of course that would be better abd I'd much prefer that. Unfortunately I haven't been able to find a single scenario in which those paths would be exercised. As far as I understand path pruning should take place e.g. when a mixer modifies audio routing and as a result disables a certain pipeline, which is then pruned. If I could reproduce such a scenario I would be able to first check whether it's working, then see exactly how it is working and then see how best to add my use case to it. Since I wasn't able to find such a scenario, my only option was to preserve the current state and add my own path "on top." I'd be happy to try the other path too, I just need a use case, that I can reproduce.

Thanks Guennadi