Bug 498007

Summary:	brightness changing to minimum at random on wake from sleep/hibernate
Product:	[Plasma] plasmashell	Reporter:	israel <israelfaustino.santos>
Component:	Power management & brightness	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	dkxls23, jpetso, kdedev, nate
Priority:	NOR
Version First Reported In:	6.2.4
Target Milestone:	1.0
Platform:	Fedora RPMs
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=487847
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	syslog before restart to restore brightness

Description israel 2024-12-29 10:27:46 UTC

Created attachment 176941 [details]
syslog before restart to restore brightness

SUMMARY
Every time I wake my laptop from sleep or hibernate, Plasma changes my screen brightness from max to low a few times and then goes to minimum brightness. I can only change it back using the scroll wheel over the brightness widget because Keyboard shortcuts won't work. And even then, it goes back to flickering and then changes it back to minimum again.

I was able to reproduce the error with and without night light enabled.

I changed the POWERDEVIL_NO_DDCUTIL=1 environment variable using the instructions found on the link below but it didn't resolve the issue.
https://www.reddit.com/r/kde/comments/1g3wzka/plasma_62_display_brightness_incorrect_after/ls1gfvd/


STEPS TO REPRODUCE
1. Put laptop to sleep or hibernate;
2. Wake it up;
3. Wait a few seconds.

OBSERVED RESULT
Screen flickers and then goes dim.

EXPECTED RESULT
Plasma remembers the brightness set by user and allows user to change it.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 41
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.9.0
Qt Version: 6.8.1
Kernel Version: 6.12.5-200.fc41.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 PRO 4650U with Radeon Graphics
Memory: 29.2 GiB of RAM
Graphics Processor: AMD Radeon Graphics

Comment 1 Armin 2024-12-30 08:48:54 UTC

I experience the same issue, i.e. when resuming from standby the laptop screen first starts to flicker, and then gradually goes dark.

I should note though that for me the issue only shows up when running on battery, the screen switches back to full brightness when I plug in a power supply. This is extremely annoying as it renders the laptop unusable without an external power supply.

This is on a Lenovo ThinkPad P14s, here my system info:
 OS: Fedora 41
 Kernel: x86_64 Linux 6.12.6-200.fc41.x86_64
 Resolution: 3440x1440
 DE: KDE
 WM: KWin
 CPU: AMD Ryzen 7 PRO 5850U with Radeon Graphics @ 16x 4.507GHz
 GPU: AMD Radeon Graphics (radeonsi, renoir, LLVM 19.1.0, DRM 3.59, 6.12.6-200.fc41.x86_64)
 RAM: 10254MiB / 27870MiB

Comment 2 Armin 2025-01-17 23:05:54 UTC

It turns out that, at least on my system, this is not related to anything in KDE, but rather a kernel bug introduced between 6.12.4 and 6.12.5. 
Kernel developers are working on a fix, which was supposed to be included in 6.12.9 (I haven't tested it yet though, and I simply reverted back to 6.12.4 for now).

Might also be that these are two different issues...

Comment 3 TraceyC 2025-03-06 20:04:52 UTC

(In reply to israel from comment #0)
> Kernel Version: 6.12.5-200.fc41.x86_64 (64-bit)

Can I ask you to try booting with the 6.12.4 kernel and see if you can reproduce this bug? Thanks.

Comment 4 Bug Janitor Service 2025-03-21 03:47:00 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 5 Bug Janitor Service 2025-04-05 03:46:55 UTC

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