Bug 505210

Summary:	kscreenlocker may freeze on unlocking with NVIDIA GPU
Product:	[Plasma] plasmashell	Reporter:	alerikaisattera
Component:	Screen locking	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED UPSTREAM
Severity:	grave	CC:	nate, vkrevs
Priority:	NOR
Version First Reported In:	6.3.5
Target Milestone:	1.0
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description alerikaisattera 2025-06-04 16:31:55 UTC

SUMMARY
Sometimes, when using an NVIDIA GPU, kscreenlocker freezes on unlock. It eventually unfreezes and can be unlocked.

When this happens, the following error messages are logged:
QRhiGles2: Context is lost.
Graphics device lost, cleaning up scenegraph and releasing RHI

STEPS TO REPRODUCE
Not exactly reproducible, but follows a pattern: in an interval between reboots, it either occurs on every unlock or doesn't occur at all

OBSERVED RESULT
kscreenlocker freezes temporarily and then unfreezes

EXPECTED RESULT
kscreenlocker doesn't freeze

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.14.0
Qt Version: 6.9.0

ADDITIONAL INFORMATION
Occurs with NVIDIA 4060 Ti. Doesn't occur with AMD

Comment 1 Nate Graham 2025-06-04 16:47:54 UTC

If it only happens on NVIDIA, then unfortunately it's an NVIDIA driver bug. It's really unfortunate that the bug is severe enough to brick the lock screen. But that's the risk of using NVIDIA, I'm afraid. :(

Please report this issue to the NVIDIA folks, either by sending an email to linux-bugs@nvidia.com or making a post at https://forums.developer.nvidia.com/c/gpu-graphics/linux. It would be helpful to the NVIDIA developers if you could run `nvidia-bug-report.sh` and attach the resulting file in your report.

Thanks!