[pulseaudio-discuss] [PATCH 0/5] No more dual-direction ports.

[David Henningsson]

2012-04-17 16:48, Mark Brown skrev:
> On Tue, Apr 17, 2012 at 04:29:01PM +0200, David Henningsson wrote:
>> For desktops / HDA, we only have single-direction ports so far, and
>> I don't see that changing in the foreseeable future, so not much to
>> worry about there.
>
> This is definitely *not* true - as I have repeatedly pointed out all the
> Apple hardware has headset jacks that are compatible with the iDevice
> headsets.  See the recent thread from Kevin Hillman on alsa-devel...

I know that there is plenty of Apple (and Lenovo etc) hardware that have 
4-pin headset jacks. I also know that for all such hardware that I've 
seen, the input and output paths are separated at the codec level - the 
mic pin node and the headphone pin node is separate, and they have 
separate jack detection. There is no way we can figure out, from 
reading/parsing the codec configuration, whether this is a 4-pin jack or 
this is one separate headphone jack and one mic jack physically.

Therefore, the 4-pin jacks show up as two different ports, one for 
headphone and one for mic. They are both single-direction ports, and 
thus, my original statement is true.

-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic