https://bugzilla.kernel.org/show_bug.cgi?id=68571
--- Comment #44 from Alex Deucher alexdeucher@gmail.com --- (In reply to andre+kernel from comment #43)
I'm experiencing the same problem with a XFX Radeon HD 7870 GHz Edition. I've tried both appending radeon.audio=0 to the kernel parameters and blacklisting snd_hda_codec_hdmi to no avail. Currently, I'm on 3.15.1, but I remember it happening on 3.14, too.
You have different hardware. This bug is specific to BTC parts. You have an SI part. Please file a new bug.