Comment 18 for bug 542550

The abovementioned patch has been included upstream in kernel 2.6.35-rc2. From the changelog:

commit 26fd74fc01991a18f0e3bd54f8b1b75945ee3dbb
Author: Daniel T Chen
Date: Sun May 30 09:55:23 2010 -0400

    ALSA: hda: Use mb31 quirk for an iMac model

    BugLink: https://launchpad.net/bugs/542550

    Symptom: On the reporter's iMac, in Ubuntu 10.04 LTS neither playback
    nor capture appear audible out-of-the-box.

    Test case: Boot from an Ubuntu 10.04 LTS live cd or from an installed
    configuration and attempt to play or capture audio.

    Resolution: Specify the mb31 quirk for this machine in the codec SSID
    table.

    Reported-and-Tested-By: f3a97
    Cc: <email address hidden>
    Signed-off-by: Daniel T Chen
    Signed-off-by: Takashi Iwai