https://bugzilla.kernel.org/show_bug.cgi?id=102401
--- Comment #6 from Alex Deucher alexdeucher@gmail.com --- (In reply to Maxqia from comment #5)
Replacing drm_detect_monitor_audio(radeon_connector_edid(connector)) with true seems to fix the problem.
This means the EDID from your monitor claims not to support audio.