Re: [PATCH] ALSA: hda/generic: Use "Input Source" for the capture source selector

[songxiebing]

>That can work, but I'd rather check further why PA doesn't work with
>Capture Source.  If it's something like an element that doesn't match
>with the actual input, it's a driver's problem and we may work around
>it somehow.  But before figuring it out, it's not wise to blindly
>work around something just because it looks as if working.
>
>
>thanks,
>
>Takashi

Thanks for reply.

What I found so far on the userspace side:

- alsa-lib's simple-mixer layer special-cases the exact name "Capture
  Source": it does *not* expose an enumerated element with that name, but
  instead creates one exclusive capture switch per enum item, named after
  the item (simple_none.c, simple_event_add()).
- PulseAudio's ALSA backend resolves its "Capture Source" element strictly
  by name (element_probe() -> snd_mixer_find_selem()), so it never finds
  an element and the mux is never switched.  PA also has no handling for
  snd_mixer_selem_has_capture_switch_exclusive(), so it can't consume the
  per-item switches either.

Thanks,
Bob