https://bugs.freedesktop.org/show_bug.cgi?id=69675
--- Comment #2 from Alex Deucher agd5f@yahoo.com ---
From IRC:
<Anssi> agd5f: you might've seen already, but the 23.976 Hz pixel clock 74175.824175 is rounded up to 74176 in Ville's commit, but r600_hdmi_predefined_acr[] table contains 74175 so it does not match <Anssi> not sure why the calculated value would not work, though... probably for the same reason the recommended value is not the calculated value, but I don't understand enough to know why