Bug 495109 - Monitor brightness is reset to 100% after boot or power cycling monitor
Summary: Monitor brightness is reset to 100% after boot or power cycling monitor
Status: RESOLVED DUPLICATE of bug 494408
Alias: None
Product: plasmashell
Classification: Plasma
Component: Power management & brightness (show other bugs)
Version: 6.2.1
Platform: Arch Linux Linux
: NOR normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-10-20 20:20 UTC by einjonas
Modified: 2025-02-28 17:38 UTC (History)
11 users (show)

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


Attachments
Brightness before turning off/on screen (3.16 MB, image/png)
2025-02-17 08:47 UTC, Tomi
Details
Brightness after turning screen on (3.16 MB, image/png)
2025-02-17 08:48 UTC, Tomi
Details

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Description einjonas 2024-10-20 20:20:03 UTC
Brightness of the monitor is at 100% after boot it resets every boot. 
It doesn't respect the monitor controls. Setting it manually it the control Panel of KDE is kinda fixing it.


Operating System: Fedora Linux 40
KDE Plasma Version: 6.2.1
KDE Frameworks Version: 6.7.0
Qt Version: 6.7.2
Kernel Version: 6.11.3-200.fc40.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 5800X 8-Core Processor
Memory: 31.2 GiB of RAM
Graphics Processor: AMD Radeon RX 6700 XT
Comment 1 RW 2024-10-21 06:08:49 UTC
I've a similar issue and maybe it's also related to https://bugs.kde.org/show_bug.cgi?id=495106 (not my issue). Similar setup as the reporter:

Operating System: Archlinux
KDE Plasma Version: 6.2.1
KDE Frameworks Version: 6.7.0
Qt Version: 6.8.0
Kernel Version: 6.11.4
Graphics Platform: Wayland
Processors: AMD Ryzen 9 3900X 12-Core Processor
Memory: 128 GiB of RAM
Graphics Processor: AMD Radeon RX 6700 XT

Besides that the brightness control sooner or later "disappears". So you can only control the "Night control" anymore but the "Brightness" slider disappears. But so far I wasn't able to figure out when this happens.
Comment 2 dannkunt 2025-02-03 12:53:00 UTC
Still relevant on 6.3.91. Brightness resets only on primary monitor(one of 4).  Also, it resets after some time in locked state. Brightness control sometimes shows only 2 monitors out of 4
Comment 3 dannkunt 2025-02-03 12:55:30 UTC
(In reply to dannkunt from comment #2)
>  on 6.3.91
I mean 6.2.91. There are no edit button
Comment 4 Tomi 2025-02-17 08:47:55 UTC
Created attachment 178462 [details]
Brightness before turning off/on screen
Comment 5 Tomi 2025-02-17 08:48:53 UTC
Created attachment 178463 [details]
Brightness after turning screen on
Comment 6 Tomi 2025-02-17 09:00:04 UTC
Brightness is yet again broken after updating from 6.2.5 to plasma 6.3.0. Monitor brightness resets back to 100% after turning off screen and then turning it back on. Issue only affects primary screen thou for some reason. Primary screen is connected through displayport and secondary screen is connected with club 3D displayport to dvi-dl active adapter. It doesn't matter if i set brightness through monitor settings or plasma control panel it always resets back to 100% if i turn screen off and then on. Reboot doesn't reproduce this issue.

Operating System: CachyOS Linux 
KDE Plasma Version: 6.3.0
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2
Kernel Version: 6.13.2-2-cachyos (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 9700X 8-Core Processor
Memory: 31.0 GiB of RAM
Graphics Processor: AMD Radeon RX 7900 XT
Comment 7 TraceyC 2025-02-25 19:26:17 UTC
*** Bug 500337 has been marked as a duplicate of this bug. ***
Comment 8 TraceyC 2025-02-25 19:35:26 UTC
I can't reproduce this on git-master or 6.3.1

Laptop, connected to external display
Set laptop to 60% and monitor to 50%
Rebooted, and both screens retained the same brightness settings
Also tried power cycling the monitor, brightness was retained

It makes me wonder what about the monitors that *are* affected are different than the ones that aren't
Comment 9 TraceyC 2025-02-25 19:36:08 UTC
Resetting the version field
Comment 10 Nate Graham 2025-02-25 19:37:33 UTC
The ddcutil version is also relevant here; what version is everyone using? AFAIK 2.2.0 is supposed to fix a lot of these issues.
Comment 11 TraceyC 2025-02-25 21:00:05 UTC
ddcutil 2.2.0 here on both machines
Comment 12 Nate Graham 2025-02-28 17:38:56 UTC
Duping to Bug 494408, which is about a code change in Plasma 6.3.2 fixing this.

If you have 6.3.2 and it doesn't fix it, please also make sure you have ddcutil 2.2.0.

If you have both Plasma 6.3.2 and ddcutil 2.2.0 and it's still not fixed, please open a new bug report about it and we'll track that slightly different issue there.

Thanks everyone!

*** This bug has been marked as a duplicate of bug 494408 ***