My last post ended with me describing some troubles getting jackd to wake after my laptop went into S3. I managed to get some debug info out of jack after running it as a dbus service through qjackctl:
ERROR: JackAudioDriver::ProcessAsync: read error, skip cycle
ERROR: ALSA: channel flush for playback failed (File descriptor in bad state)
The CPU utilization at this point goes way up.
A quick search turns up a Debian bug #601008 and bugs filed against a number of other Linux distros. There’s also an open ticket on this issue in Jack’s tracker.
So all the right people know about the issue. The Jack folks even recommend a very sane work around which is manually suspend and resume Jack before and after S3 (hacking suspend / resume manually). I like the idea of jack getting a notification over dbus even more though. That would be very clean. Hopefully we’ll see some action on this soon. Till then I’m looking for a work around.