Comment 3 for bug 114522

After some more tests and discussion on alsa-dev ML, I can consider the solution provided above as a valuable workaround. I think that the bug can be cancelled from launchpad, because probe_mask=1 allows sound to work. Moreover it seems that this has nothing to do with the kernel. Only Alsa modifications may make this behaviour to disappear.
This seems to be related to the fact that the sound card is a mixed card "sound & modem" such as described in

eric@gondor:~$ aplay -l
**** Liste des PLAYBACK périphériques ****
carte 0: Intel [HDA Intel], périphérique 0 : ALC880 Analog [ALC880 Analog]
  Sous-périphériques: 1/1
  Sous-périphérique: #0: subdevice #0
carte 0: Intel [HDA Intel], périphérique 6 : Si3054 Modem [Si3054 Modem]
  Sous-périphériques: 1/1
  Sous-périphérique: #0: subdevice #0

So, as a conclusion, in order to have such a sound card to work it is necessary to have the following line in /etc/modprobe.d/alsa-base :

options snd-hda-intel model=clevo probe_mask=1

the model may vary depending on the laptop, but "probe_mask=1" IS ncecessary.

For more information, see alsa-dev mailing-list archive for "Alsa 1.0.13 (and others) does not work on ALC880" topic.

Eric