Re: HDA pin sense and presence detect capability

[Matt Porter <mporter@embeddedalley.com>]

On Wed, Jan 25, 2006 at 04:50:40PM +0100, Arnaud Patard wrote:
> Takashi Iwai <tiwai@suse.de> writes:
> 
> > At Wed, 25 Jan 2006 16:34:22 +0100,
> > Arnaud Patard wrote:
> >> This can be achieve with the presence detect capability (0x709,0xf09): When
> >> plug/unplugging the headphones, one gets an unsollicited responsed and
> >> the driver mute the channels.
> >> 
> >> Is there something to do that in the code or should I go and code it ?
> >> Any opinion/comments about that ?
> >
> > You can find an example of such unsolicited event in
> > patch_sigmatel.c.
> 
> okay. Thanks. 
> 
> About what's done in patch_sigmatel.c : what's the point of disabling
> the output ? imho, you only need to mute the nid. 

It seemed easier to disable the actual pin nid outputs for all line outs
(thing surround) than walk back to the associated DAC nids (which can
vary on sigmatel codecs) and mute those. It accomplishes the same
thing as muting...except there's no change in mixer state.

> Also, if there are several users of similar functions and on others chips than
> sigmatel, shouldn't it be better to put something in hda_codec.c ?
 
I think so, but this was somewhat of an experimental first attempt
at this support. I just haven't had time to do much more with it yet.

-Matt


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