https://bugs.freedesktop.org/show_bug.cgi?id=77274
--- Comment #10 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #9)
I've compiled a new 3.14 vanilla kernel with this patch:
https://bugs.freedesktop.org/attachment.cgi?id=97049&action=edit
the result was that the audio over HDMI becomes working again but the above mentioned error in my dmesg is still there.
The error is harmless. It just means your monitor does not provide a speaker allocation block in the edid.