no color format choice in amdgpu

Submitted by zam..@..il.com

Assigned to Default DRI bug account

Description

Created attachment 141066
The xorg log

I have a really crappy Philips "HD ready" tv. This tv has no options to change the color format, and it always assumes full rgb. The problem is now that I upgraded my graphics card, and now with the RX 580 I'm using the amdgpu driver. amdgpu chooses YCrCb or limited RGB (but seemingly not reported as supported, so not likely) automatically instead of RGB, and all my colors look really bad. Black levels are grey and everything looks washed out and blurry.
From xorg log:
Information [ 6.523] (II) AMDGPU(0): Supported color encodings: RGB 4:4:4 YCrCb 4:4:4

If I use an adapter and plug it in via DVI instead of HDMI, it looks fine. That has its compromises though (I now have to connect my 2nd monitor by a VGA to HDMI adapter, and that has its issues). Kernel 4.18 also breaks this work-around; it doesn't recognize any resolutions, and seemingly no EDID at all. HDMI is same as before.
I also tried overriding the EDID and setting YCrCb as not supported, but failed

The solution to all of this hassle would be to have the option "output_csc" available on amdgpu as it's apparently possible with radeon

Attachment 141066, "The xorg log":
xorg_log.txt