Bug 108261

summary: HDMI audio on radeon HD5450 not working since kernel 4.0; bisected to b20932dd62f77a96124ec8f0c7ad0908b5584526; fails to revert under 4.3 so couldn't test further.


On two machines, my HD 5450 will not play HDMI audio any more since kernel 4.0, even though the same set-up works with kernel 3.18.24. Instead of working audio, I get 9 repetitions of the below message in my syslog:

sound hdaudioC1D0: HDMI ATI/AMD: no speaker allocation for ELD

Bisecting reveals:

b20932dd62f77a96124ec8f0c7ad0908b5584526 is the first bad commit
commit b20932dd62f77a96124ec8f0c7ad0908b5584526
Author: Alex Deucher <alexander.deucher@amd.com>
Date:   Fri Feb 27 10:51:40 2015 -0500

    drm/radeon/audio: update EDID derived fields in modeset
    
    We don't necessarily have an EDID at this point when
    audio detect gets called.  Ideally we'd update these
    fields in detect, but that requires a larger rework
    of the display detect code.
    
    Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

:040000 040000 062dd016364d978dc778f63fd4593b8dfd05e90e 85a53112b2d7d747481f6dbb60b1a5e25de8f0b5 M	drivers

which looks very much like it could indeed be the culprit. Unfortunately, I cannot revert this patch on the latest kernel (4.3), so I cannot test whether this is indeed the definitive problem.

Thank you for your time. Please let me know if there is anything I can report or test for you.

$ zgrep -i radeon /proc/config.gz
CONFIG_EXTRA_FIRMWARE="rtl_nic/rtl8168e-2.fw radeon/CEDAR_me.bin radeon/CEDAR_pfp.bin radeon/CEDAR_rlc.bin radeon/CYPRESS_uvd.bin radeon/CEDAR_smc.bin"
CONFIG_DRM_RADEON=y
# CONFIG_DRM_RADEON_UMS is not set
# CONFIG_FB_RADEON is not set