[alsa-devel] hda question: 'Headphone Playback Switch' cannot unmute the pin's output amplifier?

[Lin, Mengdong]

> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai at suse.de]
> Sent: Thursday, June 06, 2013 5:02 PM

> At Thu, 6 Jun 2013 05:39:00 +0000,
> Lin, Mengdong wrote:
> >
> > And could you give me some info about the relationship of "Master playback
> switch", "Headphone Playback Switch" and "Speaker Playback switch"?
> > I observed a close binding between "Master playback switch" and "Headphone
> Playback Switch": if I turn off one, then both will be turned off. It looks strange.
> > But the "Speaker Playback Switch" is independent from "Master playback
> switch": It can be turn on/off without affecting the "Master".
> > Both "Speaker Playback Switch" and "Headphone Playback Switch" are
> implemented by a output pin, why "Master" seems to be tied to "Headphone"?
> 
> Master is master.  If it's turned off, all belongings will be off.
> That is, if Master is muted, both speaker and headphone outputs are muted no
> matter what Speaker or Headphone element is set.

Thanks for clarification, Takashi!

Is this master-slave logic implemented in ALSA driver or lib?
 
> In the driver level, it must be have so.  If not, it's a bug.
> But for verifying the driver behavior, you should check without PulseAudio; PA
> may mute/unmute the active/inactive mixer elements dynamically.

I don't have pulseaudio running. 

Thanks
Mengdong