Bug 501935

Summary:	Plasma crashes when I connect external monitor on laptop with Nvidia Optimus (X11 or Wayland)
Product:	[Plasma] plasmashell	Reporter:	Normie <losogudok>
Component:	Session Management	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	crash	CC:	kdedev, losogudok, natalie_clarius
Priority:	NOR
Version First Reported In:	master
Target Milestone:	1.0
Platform:	Arch Linux
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=488603
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Normie 2025-03-24 10:24:30 UTC

STEPS TO REPRODUCE
1.  Laptop with discrete Nvidia 1050Ti
2.  Installed optimus-manager
3.  Log in on built in monitor
4.  Connect external monitor

OBSERVED RESULT

Desktop unresponsive

EXPECTED RESULT

Desktop work normally. No need for additional actions.

SOFTWARE/OS VERSIONS

Linux:  6.13.8-arch1-1 (64-bit)
KDE Plasma Version:  6.3.3
KDE Frameworks Version:  6.12.0
Qt Version:  6.8.2

ADDITIONAL INFORMATION

Every time I want to connect external monitor I need to press Ctrl+Alt+Backspace (restart X server I guess) because after connecting external monitor desktop is unresponsive. Same issue on X11 and Wayland. I use optimus-manager because I need to force Nvidia card as my main GPU for desktop rendering. My integrated  Intel® UHD Graphics 630 is too weak for desktop rendering. It struggles to have 60 FPS on external monitor. But on built in monitor everyting works fine. I noticed this bug after updating to Plasma 6.

Comment 1 TraceyC 2025-03-25 19:57:49 UTC

Can you get a backtrace of what plasmashell is doing when it's hung? You'll need to run this either from TTY or ssh'd into the system, since the desktop freezes.

Run gdb attach -p $(pidof plasmashell) in a terminal while it's hung
If it says "--Type  for more, q to quit, c to continue without paging--" at the bottom of the terminal window, press the "c" key.
When you see a prompt that says "(gdb)", type "bt" and press the enter key.
If it says "--Type  for more, q to quit, c to continue without paging--" at the bottom of the terminal window, press the "c" key.
Copy-and-paste the contents of the terminal window into a comment here.

Thanks!

Comment 2 TraceyC 2025-03-25 20:01:08 UTC

Possibly related, another bug where the screen freezes for ~10 seconds, also on a system using Optimus
https://bugs.kde.org/show_bug.cgi?id=488603

Comment 3 Bug Janitor Service 2025-04-09 03:47:06 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 4 Bug Janitor Service 2025-04-24 03:47:41 UTC

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