On 02/24/2013 08:59 PM, Ben Hutchings wrote:
On Sat, 2013-02-23 at 20:42 +0100, Adrian Lang wrote:Package: src:linux Version: 3.2.35-2 Severity: normal There are two microphones in alsamixer and Gnome 3 audio settings (i. e., pulseaudio), but I can't get any sound using either of them. I think that's the same problem as reported to [openSUSE] and [Ubuntu]. The problem persists with 3.7 (3.7.8-1~experimental.1) from experimental. [openSUSE] http://forums.opensuse.org/english/get-technical-help-here/laptop/469210-opensuse-12-1-cannot-get-internal-mic-work-lenovo-g770-laptop.html [Ubuntu] https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/938644
These are different bugs as they concern different hardware.
I happen to have a Thinkpad T420 with the same audio codec, and the internal mic works fine. (There does seem to be a problem with external mics, now that I check, but let's ignore that for now.) So this is more board-specific, not chip-specific, behaviour.
Ok. For the internal mic, this could be the cancelling out problem; see the "Inverted Internal Mic" section of this blog post [1] for more information.
...as these bugs can sometimes be very specific - when the factory finally assembles the laptop, they might select a different component just for the DMIC, that has this problem.
-- David Henningsson, Canonical Ltd. https://launchpad.net/~diwic[1] http://voices.canonical.com/david.henningsson/2012/05/22/three-audio-bugs-in-12-04/