[Intel-gfx] Really no way to get full RGB by default?

Tom Horsley horsley1953 at gmail.com
Thu Feb 13 01:05:09 CET 2014


> I built the latest git version of edid-decode,
> and I see it printing this info:
> 
>   Extended tag: video capability data block
>     YCbCr quantization: No Data (0)
>     RGB quantization: No Data (0)
> 
> If I toggle that "RGB quantization" bit (if I can figure
> out which byte it is in :-) will that be the magic
> that induces the intel driver to use full range RGB
> all the time?

I went ahead and tried that, and it didn't work, I
still get limited RGB by default, so I dug up the
kernel sources and started poking around and if I'm
reading them correctly, there is absolutely no way
to get full RGB by default if you are using a mode
that matches any of the standard CEA video modes.

Is this really correct?

Where's my kernel option to override this? :-).

Can we add a user defined extension to EDID to
change the default? (I have to override the EDID
on the kernel command line anyway to fix the
latest gnome stupidities).

Is there a program I could include in the initramfs
and change the setting really early? I certainly can't
run xrandr then.

I'm contemplating writing a program to hack
the built in table of CEA video modes in drm.ko so
the 1920x1080 at 60HZ won't match...



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