https://bugs.freedesktop.org/show_bug.cgi?id=30151
--- Comment #1 from pitamila@free.fr 2012-02-02 12:47:26 PST --- I can confirm this.
linux 3.2 graphic board hd4870
HDMI audio device seen and unmuted set in the grub kernel boot command radeon.audio=1
but when playing, no sound and no error the audio file seems to be read faster than normal (compared to the time it is played on my soundboard)