Hi Takashi, > > Can you see any problems with that? In the application code I do need > > to re-try the snd_pcm_prepare() if one fails with -EPIPE, but with this > > undo step the second snd_pcm_prepare() is able to recover the endpoint > > states, instead of hitting this problem where it tries to start things > > that are STOPPING, but also won't set things to STOPPED because > > stop_operating is false. > > Setting the stop_operating unconditionally there doesn't look right, > as there may be other error types not only the pending XRUN. > > The problem is rather specific to USB audio driver that tries to start > the stream at PCM prepare, so it's better to handle in USB audio > driver itself. That is, when -EPIPE is returned from > start_endpoints() at prepare, the driver does some action. > > I can see two options: > - Issue snd_pcm_stop_xrun() when start_endpoints() returns -EPIPE > - Repeat the prepare after the sync at snd_usb_pcm_prepare() > > The former would require a bit of change in snd_pcm_stop_xrun(), and > it relies on the application retrying the prepare. The latter would > be more self-contained. I attached two patches (totally untested) for > both scenarios. > > My gut feeling is for the latter solution, but this needs > verification. The latter solution seems to fix our problem perfectly! Thank you so much! Is there anything I can/should do to help get the change merged? Kind regards, Carl
