hdmi issues with kernel 4.18

Submitted by dav..@..il.com

Assigned to Default DRI bug account

Link to original bug (#108542)

Description

• since 4.18, the hdmi output says "12 bit"
  
• since 4.18.8 there's no video output !!
  

You can find more details in this thread

https://bbs.archlinux.org/viewtopic.php?id=241212

I did a bisection to find the bad commit for the first regression already, and that's the result:

e03fd3f300f6184c1264186a4c815e93bf658abb is the first bad commit
commit e03fd3f300f6184c1264186a4c815e93bf658abb
Author: Mikita Lipski
Date: Wed May 16 16:46:18 2018 -0400

drm/amd/display: Do not limit color depth to 8bpc

Delete if statement that would force any display's color depth higher
than 8 bpc to 8

Signed-off-by: Mikita Lipski
Reviewed-by: Harry Wentland
Signed-off-by: Alex Deucher

:040000 040000 57c7a743a10059addbfdd1a122f90c4053d377fa 13139317e62ef56db1748bf48f31f81eb986c7f8 M drivers