[alsa-devel] [PATCH v2- ALSA 1/3] HDA - Allow hda_jack_tbl to use another nid for pin sense

[Takashi Iwai]

On Wed, 23 Sep 2015 18:34:34 +0200,
Raymond Yau wrote:
> 
> > >
> > > - add sense_nid to __snd_hda_jack_add_kctl for pin sense
> > >
> > > - update slave pin sense when master pin sense change
> > >
> > > - enable unsolicited event when widcap support UNSOL
> >
> > Again, please describe at first the reason you need this change.  Then
> > start explaining about the implementation details.  For example,
> > what's the difference from the existing gated_jack.
> >
> >
> 
> I don't understand how gated jack work, but those headset mic in alc668
> dell-headset-multi does not  use its own pin sense and won't need to enable
> unsol event of the headset mic node.
> 
> As pulseaudio don't expect jack kctl can be repesent the state of headphone
> and mic
> 
> This force the driver to create a headset mic kctl which is just a copy of
> the headphone jack kctl

See what you wrote now in the above?  It's a nice introduction of the
things you're trying to solve.  This kind of information is exactly
what I asked for.  Please rephrase and put it in the changelog at the
next time.

About gated_jack: this was introduced for Chromebook for a headset.
This should work similarly like your case.  The behavior of gated /
gating jacks are:

- When a jack A has gating_jack = B: the presence of jack A depends on
  gating_jack B.  Namely, if gating_jack B is unplugged, jack A is
  treated as unplugged.

- When a jack B has gated_jack = A: jack B doesn't give an unsol event
  by itself, but it's triggered together with gated_jack A when jack A
  is plugged/unplugged.  The plug status of jack B can be read from B
  itself.

For Chromebook, A (gated) is mic pin and B (gating) is HP pin.
That is, a headset mic is detected only when the HP pin is detected.


Takashi