Comment # 10 on bug 77274 from Alex Deucher

(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.