https://bugs.freedesktop.org/show_bug.cgi?id=69729
--- Comment #23 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #22)
Bad news. On 3.12rc2 those patches don't work anymore. Same problem like at starting this crq. HDMI audio seems to be totally disabled...
In 3.12 you can enable audio on the fly with xrandr. E.g.,
xrandr --output HDMI-0 --set audio auto