[pulseaudio-discuss] [PATCH 4/4] alsa-mixer: Add "Headphone Mic" support for 3-pin ASUS netbooks

[David Henningsson]

On 06/28/2012 10:47 PM, David Henningsson wrote:
> On 06/28/2012 06:44 PM, Tanu Kaskinen wrote:
>> On Thu, 2012-06-28 at 16:27 +0200, David Henningsson wrote:
>>> Some ASUS netbooks, such as the 1015 CX, have only one 3.5 mm jack,
>>> but it can be used either as a headphone or as a mic (but not both
>>> simultaneously).
>>>
>>> This patch adds support for the "Headphone Mic" path that is used
>>> on these devices, so that we can use the jack as an external mic, and
>>> doing so without muting the speaker.
>>>
>>> BugLink: https://bugs.launchpad.net/bugs/1018262
>>> Signed-off-by: David Henningsson <david.henningsson at canonical.com>
>>
>> The patch looks good to me, but I have a question: with this "Headphone
>> Mic", will the associated input and output paths always have "unknown"
>> as the availability state when there's something plugged in?
>
> "Unknown" when it is plugged in, and "no" when it is unplugged. Maybe I
> should add the state.unplugged as well for clarity.
>
>> Does alsa
>> provide any means to figure out which one actually is being used, and if
>> so, what are we missing in pulseaudio to make this work better?
>
> There's no autodetection by the hardware of what has been plugged in.
>
> The way it's implemented in ALSA is that there is a "Input Source" kctl,
> and if you set it to "Headphone Mic" the jack retasks as mic, and if you
> set it to "Internal Mic", the jack retasks as headphone.
>
> In Windows 7, there is a popup when you plug in asking "Hey, what did
> you plug in?" and you select Headphone or Mic manually that way. I guess
> that would provide some extra level of elegance, but at least having a
> way of using the external mic would be good enough for me at this point.

Pushed.
After having done two adjustments based on feedback from people with the 
hardware.


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