Messages in this thread | | | Date | Fri, 26 Jul 2013 23:48:13 +0100 | From | Mark Brown <> | Subject | Re: [PATCH 1/4] ALSA: Added jack detection kcontrol support |
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On Fri, Jul 26, 2013 at 12:10:27PM -0700, Felipe Tonello wrote: > On Fri, Jul 26, 2013 at 11:54 AM, Mark Brown <broonie@kernel.org> wrote:
> > This isn't ideal for multi-function jacks like headsets - it will report > > a single boolean value for the jack regardless of what's plugged in > > meaning userpace can't do things like figure out if a headset or > > headphone is present. It's probably OK for any realistic input button > > since you're not going to get an input button without other things being > > present.
> The KControl for Jack is boolean anyway. You can check it with "amixer > contents". user-space can figure out based on the control name. At > least PulseAudio does that way.
No, it can't do that for headset jacks - these will be created with a single jack reporting multiple states, there's a state for headphone and a state for microphone. The system can generally distinguish between having a headset or just plain headphones inserted and act accordingly (for example, recording from the built in microphone on a phone when used with normal headpones).
> > What I'd expect to happen here is that for multi function jacks we > > create a control per function if the controls are valid.
> Do you mean based on snd_jack_types?
Yes. If there's only one function supported the current code is fine but for multiple functions it's going to discard useful information. [unhandled content-type:application/pgp-signature] | |