Bug 508912

Summary:	Failed to turn off screen and suspend/sleep when left untouched, for no reason
Product:	[Plasma] plasmashell	Reporter:	php4fan
Component:	Power management & brightness	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED DOWNSTREAM
Severity:	normal
Priority:	NOR
Version First Reported In:	6.3.6
Target Milestone:	1.0
Platform:	Manjaro
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description php4fan 2025-08-29 23:28:25 UTC

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SUMMARY

I have my laptop configured (which I think was the default) so that when I leave it untouched, the screen locks, then turns off, and then eventually the system suspends (goes to sleep), each after a certain number of minutes. So, I never manually do any of those things, I just leave my computer when I'm done using it, and it usually normally goes to sleep automatically. I very rarely reboot or shut down, only when I absolutely have to.

Now today I left my computer as I normally do half a dozen times or more per day, and I've just come back, and the screen was on and not locked. It didn't lock screen, it didn't turn the screen off, and it didn't go to sleep. It stayed "awake" for hours for no reason, doing nothing, potentially hurting the screen.

STEPS TO REPRODUCE
This is not reproducible at will, this has happened to me once.

1. Leave the computer untouched

OBSERVED RESULT

didn't lock screen, nor turn the screen off, nor go to sleep.

Additionally, the "Power and Battery" tray widget doesn't show any application preventing sleep, which it usually does when there's some (for example a video playing).

EXPECTED RESULT

should have locked screen, then turned the screen off, then gone to sleep.

SOFTWARE/OS VERSIONS
Operating System: Manjaro Linux
KDE Plasma Version: 6.3.6
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.1
Kernel Version: 6.6.101-1-MANJARO (64-bit)
Graphics Platform: Wayland
Processors: 12 × 12th Gen Intel® Core™ i7-1255U
Memory: 15.3 GiB of RAM
Graphics Processor: Intel® Iris® Xe Graphics
Manufacturer: ASUSTeK COMPUTER INC.
Product Name: Vivobook_ASUSLaptop X1502ZA_F1502ZA
System Version: 1.0

ADDITIONAL INFORMATION

Comment 1 Bug Janitor Service 2025-08-29 23:33:38 UTC

Thank you for the bug report!

However Plasma 6.3.6 no longer receives updates or maintenance from KDE; active versions are 6.4 or newer. Please upgrade to an active version as soon as your distribution makes it available to you. Plasma is a fast-moving project, and bugs in one version are often fixed in the next one.

If you need help with Plasma 6.3.6, please contact your distribution, who bears the responsibility of providing help for older releases that are no longer receiving updates from KDE.

If you can reproduce the issue after upgrading to an active version, feel free to re-open this bug report.

Comment 2 php4fan 2025-09-19 21:28:04 UTC

Something very similar or maybe the exact same thing happened today.

I left the computer untouched and the screen didn't lock. This time, when I came back, I found that there was a Google Chrome tab, NOT the focused one, that was playing a youtube video (I had left it open and forgot about it).  Crucially, the "Sleep and Screen locking" section in the Power and Battery widget did NOT show any application preventing screen locking and sleep, despite the fact that it had actually been prevented.

I'm not sure whether a video playing in a NON-FOCUSED browser tab is supposed to prevent screen lock or not. But if it does, and it does not show up in the Power and Battery widget, that is certainly 100% a bug.

What I have verified is that systematically, when I have a NON-focused Chrome browser tab playing a video, nothing shows up as preventing screen lock and screen under Power and Battery. But I haven't verified whether or not it actually systematically prevents screen lock, or if that happens only sporadically; because in order to test that I need to either wait for a long time each time, or change my settings to a shorter time and then change them back.

I cannot tell for sure if the previous time, when I originally reported this, there had also been a video playing in a non-focused tab that I missed.

So, the issue could be any of the following:
1) If video playing in the background in a non-focused Chrome tab is NOT supposed to prevent screen lock, the issue could be:
1-A) that it sometimes randomly, or perhaps systematically, does, and still doesn't show up in the widget; or
1-B) it has nothing to do with video playing in a Chrome tab: automatic screen locking, sleeping etc sometimes randomly fails
2) If video playing in a non-focused Chrome tab IS supposed to prevent screen lock, then the issue is that it systematically fails  to show up as preventing screen lock in Power and Battery.

I'm documenting this even though the bug is closed as downstream, because I'm pretty sure that, when 6.4 is finally released on stable Manjaro and I upgrade, I'll find that the issue is not fixed and this will need to be reopened.