[Bug 97442] [HSW HDMI] Audio with 44.1 khz not working when 1920x1080p screen refreshrate > 30hz

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=97442

--- Comment #5 from Mark Wilczynski <Mark_Wilczynski at hotmail.com> ---
Figured out why I couldn't reproduce the bug.  Had nothing to do with the Linux
distro.  I had the HDMI signal from the PC passing through my Denon AVR on its
way to the TV.  The AVR was turned off and in "pass-through" mode so I didn't
think it would have any effect.  But this connection made the TV speakers work
fine for 44.1 kHz audio.  After looking at the logs, I realized the AVR was
replacing the TV EDID and forcing the HDMI signal to 24-bit color from the
previous 36-bit.

Once I connected the PC directly to the TV (without AVR) I was back to broken
44.1 kHz audio regardless of distro.

Applying your 4.7 kernel patch to disable 12 bpc, fixes the 44.1 kHz audio on
this TV.  That explains why the 8 bpc EDID of the AVR also fixed the problem.

For some reason this TV does not work correctly when sending 36-bit color
signal over HDMI.  Unfortunately, I don't have another display available with a
36-bit color EDID.  All the rest report max 24-bit.  I suspect this might be
why not many other users have reported this problem.

I did some experimentation by hard-coding a custom 'N' value which in theory
was correct for a 222528 TMDS.  This fixed the audio problem with 36-bit video
but file playback remained jumpy as a result of the skipping video frames. 
Either the video pixel clock is running slightly too slow or the audio clock is
running slightly too fast compared to 148352 TMDS.  Maybe the CTS value is
still wrong but I wasn't sure hot to set that.  I guess it's derived
automatically from the pre-defined pixel clock values stored in the AUD_CONFIG
register?

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