Bug 462280

Summary: kwin (wayland) completely freezes when plugging in external screen
Product: [Plasma] kwin Reporter: Ralf Jung <post>
Component: multi-screenAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED WORKSFORME    
Severity: crash CC: nate, xaver.hugl
Priority: NOR Keywords: wayland-only
Version First Reported In: 5.26.3   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Ralf Jung 2022-11-26 16:24:48 UTC 
SUMMARY

I have a dual-GPU-laptop, where external screens are driven by the NVidia GPU.

Sometimes when I plug in the external screen while watching a Youtube video full-screen (in Firefox), the entire system just freezes. The sound keeps playing, but the machine becomes entirely unresponsive to inputs. I cannot even switch to a virtual terminal, I have to use SysRq keys to hard-reboot the machine.


SOFTWARE/OS VERSIONS
Operating System: Debian GNU/Linux
KDE Plasma Version: 5.26.3
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6
Kernel Version: 6.0.0-4-amd64 (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Xeon® CPU E3-1505M v5 @ 2.80GHz
Memory: 31,2 GiB of RAM
Graphics Processor: Mesa Intel® HD Graphics P530
Manufacturer: LENOVO
Product Name: 20ENCTO1WW
System Version: ThinkPad P50

ADDITIONAL INFORMATION
Comment 1 Ralf Jung 2022-11-27 13:30:33 UTC 
In fact this seems to be pretty much reproducible. It only doesn't happen when I go out of fullscreen before plugging in the external screen.
Comment 2 Nate Graham 2022-11-30 20:58:34 UTC 
Thanks for the bug report. Any chance you could get a backtrace of what kwin_wayland is stuck on at the moment it crashes?
Comment 3 Nate Graham 2022-11-30 20:58:46 UTC 
...Er, when it freezes.
Comment 4 Ralf Jung 2022-11-30 21:06:24 UTC 
The machine is completely unresponsive at that point. Ctrl-Alt-Backspace does nothing. Ctrl-Alt-F1 (to 12) does nothing. I do not have a 2nd machine I could use to SSH into the laptop. Unless you have some other idea, I don't know how to get a backtrace here.
Comment 5 Zamundaaa 2022-12-03 14:57:57 UTC 
You can use termux on a phone to ssh into the laptop
Comment 6 Zamundaaa 2023-12-13 17:37:12 UTC 
Is this still happening with 5.27?
Comment 7 Ralf Jung 2023-12-13 18:24:10 UTC 
I've switched my setup and no longer use KDE, so I can't test this, sorry.