Bug 513978

Summary: HDR broken brightness and black levels
Product: [Plasma] kwin Reporter: bio3c
Component: colour-managementAssignee: KWin default assignee <kwin-bugs-null>
Status: REPORTED ---    
Severity: normal    
Priority: NOR    
Version First Reported In: 6.5.4   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description bio3c 2025-12-30 16:06:06 UTC 
SUMMARY
On games like TLOU 1 brightness is broken with HDR on, KWIN_DISABLE_TONEMAPPING=1 does help a little, still looks off, on
DOOM Eternal (vulkan app) blacks look crushed with HDR on, disabling tonemapping doesn't help.

I'm almost certain this happened due to the recent plasma upgrade, pacman.log shows kwin (6.4.5-4 -> 6.5.4-3), plasma-desktop (6.4.5-4 -> 6.5.4-1) because i always tried using the LTS kernel instead of mainline, downgrading mesa and proton to a much older version and that didn't change anything.

This problem happens either with wine wayland or gamescope.

STEPS TO REPRODUCE
Launch TLOU 1 and check the brightness options, setting to HDR makes it look washed out
Or launch Doom Eternal, should look terrible, kinda like posterization

SOFTWARE/OS VERSIONS
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: 6.5.4
KDE Plasma Version:  6.5.4
KDE Frameworks Version:  6.21.0
Qt Version: 6.10.1

ADDITIONAL INFORMATION

Operating System: EndeavourOS 
Kernel Version: 6.19.0-rc3-1-mainline (64-bit)
Graphics Processor: AMD Radeon RX 9070 XT