[alsa-devel] Dynamic HDMI PCM creation

[Takashi Iwai]

Hi David,

as we discussed at Plumbers, I tried some hack to create/delete
HDMI/DP PCM stream per hotplug/unplug.  Test patches are found in
sound-unstable git tree topic/hdmi-dynamic-pcm branch
  git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-unstable.git

The patches are all small and easy, but it's still in a pretty rough
cut.  It won't handle some cases, e.g. unplug during suspend, or
such, I'm afraid.  After all, it's just a test.

With these patches, the PCM device appears and disappears properly
upon HDMI/DP hotplug/unplug on my system.  On mine, it appears as
/dev/snd/pcmC0D8 as it's an Intel on-board.  So far, so good.

Now the problem is that PA gets confused when this happens.  It can
switch to HDMI/DP, but then the analog output disappears from PA's
profile.  You cannot switch back to analog output after that, even
after you unplug HDMI/DP cable.

Or, it might be my PA version...  I'll check newer one.
But it'd be good if you also check in your side.


thanks,

Takashi