[alsa-devel] Separate input and output jacks for one UCM device?

[Tanu Kaskinen]

On Thu, 2015-04-02 at 08:28 -0700, Dylan Reid wrote:
> On Wed, Apr 1, 2015 at 5:27 AM, Liam Girdwood
> <liam.r.girdwood at linux.intel.com> wrote:
> > On Tue, 2015-03-31 at 19:49 +0300, Tanu Kaskinen wrote:
> >> So is your preference that UCM configuration authors are forced to
> >> define simplex devices to deal with headset jacks, rather than using
> >> duplex devices and defining "PlaybackJackControl" and
> >> "CaptureJackControl" separately? (I don't personally mind either way.)
> >
> > I don't really mind either, but what's easier for audio servers like
> > pulseaudio that will be the main UCM clients ? I guess that pulseaudio,
> > CRAS, and other audio servers probably deal with simplex PCM streams
> > internally so mapping to simplex jacks/devices might be better ?
> 
> There is an advantage to having a separate device for the headphone and mic
> even if they are connected to the same jack.  The user can enable one and not
> the other, most commonly to use the headphones but record from the built-in mic,
> ignoring the headset mic.  Because of this we require all ChromeOS devices to
> support separate reporting and selection of headphone/mic on the headset jack.
> There is always one UCM device and one user-visible i/o node per jack.

I'm not sure what you mean... "There is always one UCM device [...] per
jack" sounds like you want there to be only one device representing
headset, but on the other hand you talk about it being advantageous to
have a separate device for the headphone and mic... Can you clarify the
number of UCM devices per physical headset jack?

-- 
Tanu