https://bugs.freedesktop.org/show_bug.cgi?id=69675
--- Comment #3 from Alex Deucher agd5f@yahoo.com --- Created attachment 86598 --> https://bugs.freedesktop.org/attachment.cgi?id=86598&action=edit use hw generated cts and n values rather than the sw programmed values
Does this patch help? If not, it may be worth adding some slop to the r600_hdmi_predefined_acr[] table to handle rounding differences so the appropriate defined values get selected.