Bisect complete:

b1f6f47e3e33c4a74534f1301aca241ffabbb3a0 is the first bad commit
commit b1f6f47e3e33c4a74534f1301aca241ffabbb3a0
Author: Alex Deucher <alexander.deucher@amd.com>
Date:   Thu Apr 18 10:50:55 2013 -0400

    drm/radeon: clean up audio dto programming

    Split into DCE2/3 and DCE4/5 variants. Still todo is to
    calculate the DTO dividers properly.  Add proper formula
    to the comments.

    Reviewed-by: Christian König <christian.koenig@amd.com>
    Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

:040000 040000 b60cf880f2227596705391e71a56aaa12e1eb61c
a723f4928d1a20bcd0b5759077360f9342c9eecc M    drivers