Launching pavucontrol may still freeze the system, hence snd_hda_codec_hdmi has to be blacklisted (losing its required functionality), also under kernel 3.8.0-30 and even after a BIOS update to 1.32 (irrevocable, cf. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1203446/+attachment/3809189/+files/HPQFlash.png).
$ sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date 786F1 v01.32 07/21/2011
Launching pavucontrol may still freeze the system, hence snd_hda_codec_hdmi has to be blacklisted (losing its required functionality), also under kernel 3.8.0-30 and even after a BIOS update to 1.32 (irrevocable, cf. https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/1203446/ +attachment/ 3809189/ +files/ HPQFlash. png).
$ sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date
786F1 v01.32
07/21/2011