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

[Takashi Iwai <tiwai@suse.de>]

On Thu, 22 Oct 2026 11:29:21 +0200,
songxiebing wrote:
> 
> >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.

If that's true, PA is broken for all other AC97-based PCI cards?
Let's verify the PA behavior more at first.


Takashi