Broken colors on RX 5700 with adjusted brightness

Submitted by Miroslav Lichvar

Assigned to Default DRI bug account

Link to original bug (#112148)

Description

I have an RX 5700 card connected to a monitor which doesn't display dark colors very well. The brightness needs to be adjusted in software. I use the xcalib tool like this:

xcalib -c
xcalib -a -b 10 -co 90

This displays dark colors well, but some images/videos have weird artifacts. After playing with a color picker it looks like colors that have the green component zero are much brighter than they should be. For example, color #750000 is much brighter than #750100. I'll attach some images that show the problem.

When the monitor is connected to a different computer (with a non-AMD GPU) configured with the same xcalib commands, the problem disappears, so it seems to be specific to the hardware/driver.

Please let me know if you need more information.

Installed packages:
kernel-5.3.6-300.fc31.x86_64
xorg-x11-server-Xorg-1.20.5-7.fc31.x86_64
xorg-x11-drv-amdgpu-19.1.0-1.fc31.x86_64
mesa-dri-drivers-19.2.0-1.fc31.x86_64
xcalib-0.8-24.fc31.x86_64