Bug 490567

SUMMARY
When using HDR with a refresh rate => 144 Hz the top side of my screen starts flickering, note that this doesn't happen at 180Hz with HDR Off nor 120Hz with HDR On. This happened after updating to KDE Plasma 6.1.3 from 6.1.2 and I use Wayland. Not sure if this is a bug from KScreen, KWin or other component.

STEPS TO REPRODUCE
1. Set refresh rate to 180Hz.
2. Enable HDR.

OBSERVED RESULT
Top side of the screen flickers when movement occurs.

EXPECTED RESULT
There shouldn't be any flicker.

SOFTWARE/OS VERSIONS
Windows: -
macOS: -
Linux/KDE Plasma: NixOS 24.11 (Vicuña), Linux 6.10.0 / KDE Plasma 6.1.3
(available in About System)
KDE Plasma Version: 6.1.3
KDE Frameworks Version: 6.4.0
Qt Version: 6.7.2

ADDITIONAL INFORMATION
Adaptive sync is set to "Never"
Mesa version is 24.1.2
GPU is AMD Radeon RX 6650 XT

You can get my NixOS configuration at https://github.com/NolanPG/NixOS-General if you need it for testing, the host used is "desktop" and you'll have to change the hardware_configuration.nix before testing.

If you need any more info from my system like specifications or logs I'll provide them gladly.


You can see a video of the bug here:
https://www.dropbox.com/scl/fi/v7i0wfd5en36o8nlkml4x/20240720_184918.mp4?rlkey=go9ulhe5lfwgd90r5q9pryogm&st=iai287p4&dl=0

Sorry for the recording quality, OBS using Pipewire doesn't capture the bug but this isn't a hardware problem because this configuration (HDR at 180Hz) works in KDE Plasma 6.1.2 tested using a previous NixOS generation.