https://bugs.freedesktop.org/show_bug.cgi?id=70053
--- Comment #2 from Alex Deucher agd5f@yahoo.com --- Created attachment 87006 --> https://bugs.freedesktop.org/attachment.cgi?id=87006&action=edit possible fix
Does this patch help? Seems like maybe your system isn't getting ac events properly. Can you attach the dmesg output of this patch?