$ uname -a
Linux nbb 3.2.1-2-ARCH #1 SMP PREEMPT Mon Jan 23 12:40:01 UTC 2012 x86_64 Intel(R) Xeon(R) CPU W3520 @ 2.67GHz GenuineIntel GNU/Linux
I have an Intel ADA198x HD Audio interface (I believe this is a relatively standard onboard audio controller) with digital optical out via SPDIF. The digital out feeds into a receiver, which acts as a DAC for my headphones and speakers.
I'm using alsa, and as I'm using KDE then Phonon is running with a gstreamer backend.
After first booting, if I go to systemsettings and click Multimedia, then go to the Phonon tab and click "Test" then I usually get sound out of the digital port. But then I went to go play some music, and nothing came out. I messed around with a few other things (VLC is set to use digital audio), then I went back to systemsettings. Now it tells me the SPDIF interface is disabled, and when I press the "Test" button it falls back to analog and sound comes out of the analog speakers (but not the digital port).
UPDATE: I suspect something is grabbing the audio device and not releasing it. On startup, I can play music using VLC. But then when I start Firefox and try to play music from a cloud player, I get no sound, I can't play music anywhere, and the above problems occur.
How can I get this working?