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LG 27GL850: no HDR via DisplayPort, but via HDMI

Brief summary of the problem:

When connected via HDMI, I can turn HDR on and the monitor OSD reports HDR input. However, connecting via DisplayPort, there is no option to do that and forcing it i.e. through kscreen-doctor results in washed out image.

Wayland KDE plasma 6 beta 1 session.

Hardware description:

  • CPU: Ryzen 5 7640U
  • GPU: Advanced Micro Devices, Inc. [AMD/ATI] Phoenix1 [1002:15bf] (rev cb) (760M)
  • System Memory: 2x16GB
  • Display(s): LG 27GL850 (3rd page if filtering by manufacturer LG)
  • Type of Display Connection: DP or HDMI

System information:

  • Distro name and Version: arch linux
  • Kernel version: 6.6.7-arch1-1
  • Custom kernel: no
  • AMD official driver version: amdgpu using today's mesa-git and linux-firmware-git

How to reproduce the issue:

  • connect via HDMI
  • enable HDR input
  • verify monitor OSD confirms HDR was detected
  • re-connect via DisplaPort
  • there is no option to turn on HDR

Log files