The info you provided above shows that Ubuntu 12.04.2 LTS is using a linux 3.2 based kernel. In this kernel, HDMI audio on AMD/ATI GPUs has been disabled by the upstream kernel developers as it causes blank screens on a lot of systems.
You can re-enable HDMI audio by adding radeon.audio=1 to your GRUB kernel boot options as described at https://help.ubuntu.com/community/Grub2/Troubleshooting#Editing_the_GRUB_2_Menu_During_Boot Ubuntu 14.04 "Trusty Tahr" LTS is based on the linux 3.13 kernel. The radeon.audio=1 kernel boot option is no longer necessary with this kernel. Instead, HDMI audio on ATI/AMD Radeon cards can be enabled and disabled on the fly by typing the following in a terminal window: xrandr --output HDMI-0 --set audio on or xrandr --output HDMI-0 --set audio off If your HDMI port is numbered differently (type "xrandr" to check) - you might need to change HDMI-0 in the above command to HDMI-1 or HDMI-2. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1172826 Title: [HP Pavilion dv7 Notebook PC, ATI RS690/780 HDMI, Digital Out, HDMI] Playback problem (No sound in some applications) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1172826/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
