Bug 505290 - Loss of ability to adjust screen brightness occurs randomly
Summary: Loss of ability to adjust screen brightness occurs randomly
Status: REPORTED
Alias: None
Product: plasmashell
Classification: Plasma
Component: Power management & brightness (other bugs)
Version First Reported In: 6.3.5
Platform: Other Linux
: NOR normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords: usability
Depends on:
Blocks:
 
Reported: 2025-06-06 19:37 UTC by Vartan
Modified: 2025-11-25 21:59 UTC (History)
3 users (show)

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


Attachments
Brightness control slider gone from settings screen (176.08 KB, image/png)
2025-06-06 19:37 UTC, Vartan
Details
Brightness control slider restored following reboot of system (190.78 KB, image/png)
2025-06-06 19:39 UTC, Vartan
Details

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Description Vartan 2025-06-06 19:37:38 UTC
Created attachment 182074 [details]
Brightness control slider gone from settings screen

SUMMARY

Cannot control screen brightness. 

STEPS TO REPRODUCE
1.  Nothing... the problem manifests periodically, presumably randomly.  

2.   When the problem occurs, I try to hit the brightness controls (less brightness, more brightness) on my keyboard, but there is no response from the display.

3.  Alternatively, I go to the System Settings -> Display Configuration pane.  There is no "Brightness control" slider.  When the problem occurs, this slider has disappeared.  

4.  I have to reboot my system to clear the problem. 

OBSERVED RESULT

No change in brightness occurs.  
The "Brightness control"  on the System Settings -> Display Configuration pane has disappeared. 

EXPECTED RESULT

I should be able to adjust the screen brightness up or down by either hitting the brightness control keys on my keyboard OR via the System Settings -> Display Configuration pane. 

SOFTWARE/OS VERSIONS

Operating System: Fedora Linux 42
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.14.0
Qt Version: 6.9.0
Kernel Version: 6.14.9-300.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7840HS w/ Radeon 780M Graphics
Memory: 27.1 GiB of RAM
Graphics Processor: AMD Radeon 780M


ADDITIONAL INFORMATION

This problem appears randomly but quite frequently.  

If I update my system via dnf, I ALWAYS reboot immediately to avoid conflict between incompatible changes to various shared objects or applications.  

I've attached screen grabs.
Comment 1 Vartan 2025-06-06 19:39:29 UTC
Created attachment 182075 [details]
Brightness control slider restored following reboot of system

After I reboot, the brightness control slider is present on the 
System Settings -> Display & Monitor pane.

And I am also able to adjust screen brightness via the keyboard keys.
Comment 2 TraceyC 2025-09-23 17:37:03 UTC
There were fixes related to this in Plasma 6.3 with ddcutil 2.2.1 or later
Are you still experiencing this bug with ddcutil 2.2.1 or later?
Comment 3 Vartan 2025-09-23 19:31:14 UTC
(In reply to TraceyC from comment #2)
> There were fixes related to this in Plasma 6.3 with ddcutil 2.2.1 or later
> Are you still experiencing this bug with ddcutil 2.2.1 or later?

I just installed ddcutil 2.2.1-1.fc42 
I'll run my system for a few days to test and see if I can still reproduce the problem.
Comment 4 Vartan 2025-09-26 19:39:43 UTC
The problem is extant as of today's observations.