Bug 495268 - Colours washed out in sdr and hdr mode
Summary: Colours washed out in sdr and hdr mode
Status: RESOLVED NOT A BUG
Alias: None
Product: kwin
Classification: Plasma
Component: colour-management (show other bugs)
Version: 6.2.1
Platform: Fedora RPMs Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-10-23 20:29 UTC by r.hessel.git
Modified: 2024-10-24 16:40 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Drm info hdr off (50.61 KB, text/plain)
2024-10-23 20:29 UTC, r.hessel.git
Details
Drm info hdr on (51.32 KB, text/plain)
2024-10-23 20:30 UTC, r.hessel.git
Details
Kscreen doctor hdr off (1.63 KB, text/plain)
2024-10-23 20:31 UTC, r.hessel.git
Details
Kscreen doctor hdr on (1.83 KB, text/plain)
2024-10-23 20:31 UTC, r.hessel.git
Details
Filtered journal (16.24 KB, text/plain)
2024-10-23 20:32 UTC, r.hessel.git
Details
Sddm rendering nicely (3.03 MB, image/jpeg)
2024-10-23 20:34 UTC, r.hessel.git
Details
Screen still showing 10bit colour mode after restart with hdr off (121.35 KB, image/jpeg)
2024-10-23 20:37 UTC, r.hessel.git
Details

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Description r.hessel.git 2024-10-23 20:29:53 UTC
Created attachment 175160 [details]
Drm info hdr off

SUMMARY
Up until now things were working fine, so it might be a recent update or I tripped something. 

In sddm with hdr mode disabled, and a reboot, colours look fine. But the moment I log into plasma all the colours are washed out, even though hdr is disabled. Turning the TV off and on it seems to think it's still in hdr mode. Even powering it off at the wall has no effect. 

Same process, but hdr on, fresh reboot, sddm looks perfectly fine, log in, colours are washed out, just not as badly. The funny thing is, this was working. And I haven't adjusted hdr brightness offset at all (locked at 350%).

Kernel versions make no difference. 

STEPS TO REPRODUCE
1. Have hdr screen connected. (hdr on or off)
2. Log in to plasma. 

OBSERVED RESULT
Washed out colours regardless of hdr enabled, and regardless of fresh reboots and screen power cycles. 

EXPECTED RESULT
Colours should not be washed out, regardless of hdr mode. 
Suspect: screen is not actually being switched out of hdr, and something else as well, otherwise atleast hdr would look fine.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 40, kernel 6.11.4-201.fc40.x86_64
KDE Plasma Version: 6.2.1
KDE Frameworks Version: 6.7.0
Qt Version: 6.7.2

ADDITIONAL INFORMATION
Comment 1 r.hessel.git 2024-10-23 20:30:34 UTC
Created attachment 175161 [details]
Drm info hdr on
Comment 2 r.hessel.git 2024-10-23 20:31:15 UTC
Created attachment 175162 [details]
Kscreen doctor hdr off
Comment 3 r.hessel.git 2024-10-23 20:31:40 UTC
Created attachment 175163 [details]
Kscreen doctor hdr on
Comment 4 r.hessel.git 2024-10-23 20:32:17 UTC
Created attachment 175164 [details]
Filtered journal
Comment 5 r.hessel.git 2024-10-23 20:34:22 UTC
Created attachment 175165 [details]
Sddm rendering nicely
Comment 6 r.hessel.git 2024-10-23 20:37:54 UTC
Created attachment 175167 [details]
Screen still showing 10bit colour mode after restart with hdr off
Comment 7 r.hessel.git 2024-10-24 08:36:49 UTC
Just noting I'm happy to gather any additional information, this is 100% reproducible (well its technically stuck like this).
So anything I need to do I'm more than happy to.
Comment 8 Zamundaaa 2024-10-24 14:02:35 UTC
(In reply to r.hessel.git from comment #6)
> Created attachment 175167 [details]
> Screen still showing 10bit colour mode after restart with hdr off
The bit depth does not have any relationship to colors, it's just a resolution.

As KWin's running in both SDDM and your user, I don't think it can be the cause of the problem. Maybe your screen does something stupid when DDC/CI is used? Try putting POWERDEVIL_NO_DDCUTIL=1 into /etc/environment, and check if that changes anything after a reboot
Comment 9 r.hessel.git 2024-10-24 16:40:34 UTC
I'm so sorry to have wasted your time.

Somehow I managed to accidentally adjust the brightness, which is something I never do on this machine.

And turns out I checked in the wrong place (in system settings, where I couldn't find it). 

Gonna remove that applet now.

This was really silly of me, I'm usually as thorough as I can possibly be before opening a bug report.