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

[Takashi Iwai]

At Thu, 6 Jun 2013 10:34:36 +0000,
Lin, Mengdong wrote:
> 
> > -----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?

It's purely in the driver.


Takashi