RESOLVIDO Aqui : link
Solução para este final de 2011 Imac =
There is no need to apply the patch above, because it is already there on your ubuntu, my procedure:
1 - By logic recognized which the lines in green mean the extra fix lines of the patch
2 - using gksudo nautilus, then nautilus search feature, located the patch_cirrus.c and entered there with full write privileges(due to gksudo)
3 - using gedit search feature discovered which one of the patch green lines was already there.
After some additional thinking I noticed which one of the patch lines is close to other lines whose content are exactly used on /etc/modprobe.d/alsa-base.conf to solve such kind of problems. The alsa list of supported models for the cirrus codec is not updated yet to include that(not sure if it will); no matter if you get the list from your own ubuntu or from the internet. There was no way to know this model existed without benzodiaz help.
So, open your terminal and:
1 - sudo gedit /etc/modprobe.d/alsa-base.conf
2 - add to end of the file "options snd-hda-intel model=imac27_122"(only the stuff inside the quotes), save and reboot.
This worked for me, the only fix from several and several others I tried. What a pleasant surprise, the fix was already there since this year january, it was only hidden.
PS: Thanks a lot for the tip benzodias
Last edited by Lunarts; June 21st, 2012 at 04:34 AM.