[alsa-devel] [PATCH] thinkpad-acpi: Enable microphone mute LED

[Andrew Lutomirski]

On Fri, May 27, 2011 at 12:48 PM, Matthew Garrett <mjg59 at srcf.ucam.org> wrote:
> On Fri, May 27, 2011 at 12:39:10PM -0400, Andrew Lutomirski wrote:
>
>> I don't have docs so I don't really know.  But the mute LED does not
>> appear to be controllable from the LED interface and when mute is lit
>> there's no sound regardless of what ALSA thinks.  When I light the
>> micmute light, I can still record sound just fine.
>>
>> The mic mute button does nothing on Windows unless the special driver
>> is installed, and that driver seems to mute the Windows mixer, so I
>> think there's nothing special other than a little userspace helper
>> going on.
>
> Hm. That makes things kind of tricky. While it's easy to just expose the
> LED, really we want to do it in such a way that userspace knows which
> LEDs it should be toggling while setting the microphone mute.

One thought: call the thing laptop::micmute and teach userspace to
look for an led with that name.

Do any of the ALSA or PulseAudio people have any preferences?

--Andy