amdgpu wrong colors with rx460 connected via hdmi

Submitted by Reimar Imhof

Assigned to Default DRI bug account

Link to original bug (#105177)

Description

When monitor is connected via hdmi I get wrong colors. This appears during boot before the gui (x.org) gets started (frame buffer boot animation). Wrong colors (sort of violet instead of black) also appear on frame buffer text console and with x.org gui.
This bug appears with and without "amdgpu.dc=1" kernel parameter.
While running x.org I've turned the monitor off and on again. This gives correct colors but the screen resolution goes to 1024x768. So it's no work around.

The bug does not occur if the monitor is connected via dvi.

System:
Kernel 4.15.4
openSuse 42.3