Alessandro - HDMI audio on ATI Radeon hardware was 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 boot options - see https://help.ubuntu.com/community/Grub2/Troubleshooting#Editing_the_GRUB_2_Menu_During_Boot. This issue is being tracked in bug #897008.
Alessandro - HDMI audio on ATI Radeon hardware was 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 boot options - see https:/ /help.ubuntu. com/community/ Grub2/Troublesh ooting# Editing_ the_GRUB_ 2_Menu_ During_ Boot. This issue is being tracked in bug #897008.