The 3.11 kernel with radeon.audio=1 should work also, it's the method I was using before. But your system could behave differently as it's a different and more modern radeon card (HD 7770 in your case).
If the 3.11 kernel does not have the support for it (you could check in some linux kernel forum to be sure), then it's not probable that Ubuntu 13.10 would backport it from kernel 3.13 and would be better to wait for Ubuntu 14.04 that already includes the new kernel with proper HDMI audio support. So to recap: if you need the audio, update the kernel to 3.13, but remember that you'll not get it updated until the default in your Ubuntu version reaches it. This includes security updates... So it's a features vs. security updates decision :) ** Summary changed: - not HDMI output option (audio) xserver-xorg-video-ati (1:7.2.0-0ubuntu10) + No HDMI output option (audio) xserver-xorg-video-ati (1:7.2.0-0ubuntu10) ** Summary changed: - No HDMI output option (audio) xserver-xorg-video-ati (1:7.2.0-0ubuntu10) + No HDMI audio on Radeon HD 7770 xserver-xorg-video-ati (1:7.2.0-0ubuntu10) -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in Ubuntu. https://bugs.launchpad.net/bugs/1268229 Title: No HDMI audio on Radeon HD 7770 xserver-xorg-video-ati (1:7.2.0-0ubuntu10) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/1268229/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp