Bug 421829

Summary:	Plasma always freezes when changing window manager settings
Product:	[Plasma] kwin	Reporter:	elman <elman>
Component:	wayland-generic	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED FIXED
Severity:	major	CC:	david.decos, fabian, kde, nate, postix, yamiyukisenpai
Priority:	NOR
Version First Reported In:	5.22.3
Target Milestone:	---
Platform:	Manjaro
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description elman 2020-05-20 16:14:40 UTC

SUMMARY
Everytime I change some settings related to window manager, whole Plasma on Wayland freezes. For example when I change window rules or when I change compositor settings or when I change window decorations. All I need to do is click save and whole screen freezes. Music continues to play, so system is not dead. Also pressing Ctrl+Alt+Backspace works. I suspect problem might be with reloading window manager.

I set severity to critical since it renders my computer unusable and I loose all my work.

STEPS TO REPRODUCE
1. Click any window
2. Add window rules
3. Click save

OBSERVED RESULT
Whole Plasma freezes.

EXPECTED RESULT
Settings are saved and I can continue to work.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Manjaro Stable
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.70.0
Qt Version: 5.14.2

ADDITIONAL INFORMATION
Is there any extra information I can provide?

Comment 1 David de Cos 2020-11-25 14:53:16 UTC

I can confirm this bug, just as elman@seznam.cz described.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: OpenSuSE Leap 15.2
KDE Plasma Version: 5.20.3
KDE Frameworks Version: 5.76.0
Qt Version: 5.15.1

Comment 2 Nate Graham 2021-03-04 20:02:01 UTC

I cannot reproduce with current git master. Can someone who is able to reproduce the issue provide more detailed steps I can follow?

Comment 3 elman 2021-03-05 08:03:41 UTC

I retested all 3 issues:

- when I change window rules
- when I change compositor settings
- when I change window decorations

on Plasma 5.21.2 and can't reproduce any of them. Hopefully they are all fixed.

Comment 4 Vlad Zahorodnii 2021-03-05 10:06:15 UTC

Please re-open this bug report if this issue comes back.

Comment 5 David de Cos 2021-03-05 10:18:45 UTC

Sorry, but I have to reopen it. In my up-to-date openSUSE 15.2 it still happens. If I change window decorations, my Wayland session still freezes, just as it did before. This is my system:

Operating System: openSUSE Leap 15.2
KDE Plasma Version: 5.21.2
KDE Frameworks Version: 5.79.0
Qt Version: 5.15.2

I'll upload a video (taken with my phone) so you can see it.

Comment 6 David de Cos 2021-03-05 10:40:47 UTC

Here's the video:
https://www.dropbox.com/s/9xfhn596z02cftn/Bug%20421829%20-%20Wayland%20freezing.mp4?dl=0

At the beginning you can see my system info. Then, when I change the window decorations, everything freezes, the countdown stops, and I can't click on anything anymore.

Comment 7 Fabian Vogt 2021-07-15 14:48:40 UTC

Happens for me on 5.22.3 as well, 100% reproducible.

What's needed for diagnosis? I can't find anything relevant in the logs.

Comment 8 Fabian Vogt 2021-07-15 14:49:34 UTC

*** Bug 439766 has been marked as a duplicate of this bug. ***

Comment 9 Fabian Vogt 2021-07-16 09:02:31 UTC

(In reply to Fabian Vogt from comment #7)
> Happens for me on 5.22.3 as well, 100% reproducible.
> 
> What's needed for diagnosis? I can't find anything relevant in the logs.

As requested by Vlad, I checked pendingFrameCount of the RenderLoop instance, and it's indeed stuck at 1. drmHandleEvent is never called FWICT.

Comment 10 elman 2021-08-20 08:26:57 UTC

I just checked on Plasma 5.22.4 / KF 5.85.0 / Qt 5.12.2 / Arch Linux and whole desktop froze when I tried to add window rule (position and size). So bug still manifests.

Comment 11 postix 2022-07-28 11:29:56 UTC

Can you still reproduce it with some more recent version of Plasma?

Comment 12 David de Cos 2022-07-28 11:44:19 UTC

I can't reproduce it anymore in an updated system:

Operating System: openSUSE Leap 15.3
KDE Plasma Version: 5.25.3
KDE Frameworks Version: 5.96.0
Qt Version: 5.15.5

Comment 13 elman 2022-08-01 22:03:42 UTC

I also can't reproduce it on fully updated Manjaro Unstable and Arch. Both have Plasma 5.25.3, KF 5.96.0 and Qt 5.15.5+kde+r174-1.

Comment 14 Nate Graham 2022-08-01 22:27:34 UTC

Ok cool, I guess it got fixed.