Comment 18 for bug 549289

The above fix by adding extra line in alsa-base.conf:
        options snd-hda-intel model="olpc-xo-1_5"
 also solved my problem (Lucid, Thinkpad X100e, pebble 20582).

Another issue arose after the fix though.
My internal mic simply didn't work then, sounds like a side effect, and I've no idea how to fix that. I tried to install the latest ALSA drivers (1.23 release), just in vain.
When I test the mic by "arecord -vv -fdat my.wav", that's indeed a file generated, but when playing back the generated file, nothing went out. Using audacity to open the my.wav showed no waves.

Before upgrading to Lucid, the mic used to work well.Hanging around the web for a while without any suggestion found yet.Hopes any one can figure out the root cause and suggest some workarounds.

Thanks!