Bug 488539

Summary:	After booting the system or waking from sleep, the brightness of DDC-capable monitors does not match the value set using the system tray applet
Product:	[Plasma] plasmashell	Reporter:	Pavel Urusov <pavel.urusov>
Component:	Power management & brightness	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	kdedev, natalie_clarius, nate
Priority:	NOR
Version First Reported In:	6.0.5
Target Milestone:	1.0
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Pavel Urusov 2024-06-15 15:13:26 UTC

SUMMARY

Every time I boot my PC or wake it from sleep, Plasma sets the brightness of my external monitor (LG 24UD58 connected to an AMD GPU) to 50% despite the fact that I set it to 100% using the control in the system tray. The brightness does not go back to 100% unless I manually lower it and then raise it again. This does not happen in other desktop environments, e.g. GNOME.


STEPS TO REPRODUCE
1. Boot KDE Plasma 6 on a system with a DDC-capable monitor connected.
2. Observe the issue.

OBSERVED RESULT

The brightness of the external monitor is set to 50% (confirmed using the monitor's menu) despite the fact that the system tray applet shows that the brightness is set to 100% (which is the correct user-specified value).

EXPECTED RESULT

The brightness is set to the user-specified value after the system boots or wakes from sleep.

Additionally, it would be very nice if there was a toggle in the settings to prevent Plasma from messing with external monitors.

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20240613
KDE Plasma Version: 6.0.5
KDE Frameworks Version: 6.3.0
Qt Version: 6.7.1
Kernel Version: 6.9.3-1-default (64-bit)
Graphics Platform: Wayland
Graphics Processor: AMD Radeon RX 560 Series

ADDITIONAL INFORMATION

Comment 1 TraceyC 2025-03-06 20:26:47 UTC

To narrow down the problem, we need some more information:
- How is the monitor connected?
- Can you paste the output of `kscreen-doctor -o`?

Thanks.

Comment 2 Bug Janitor Service 2025-03-21 03:46:53 UTC

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

Thank you for helping us make KDE software even better for everyone!

Comment 3 Bug Janitor Service 2025-04-05 03:46:51 UTC

🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.