Bug 488398 - Hardware cursor sometimes jumps when changing icons
Summary: Hardware cursor sometimes jumps when changing icons
Status: RESOLVED FIXED
Alias: None
Product: kwin
Classification: Plasma
Component: general (other bugs)
Version First Reported In: git master
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-06-12 05:20 UTC by serfreeman1337
Modified: 2025-08-11 05:11 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:

Attachments
hw cursor jump (3.02 MB, video/webm)
2024-06-12 05:20 UTC, serfreeman1337 		Details
View All Add an attachment

Note You need to log in before you can comment on or make changes to this bug.
Description serfreeman1337 2024-06-12 05:20:28 UTC 
Created attachment 170401 [details]
hw cursor jump

SUMMARY
Hardware cursor sometimes jumps when moving over the area that changes its icon.
It's only noticeable on screen, no issue with screen recording. 
See attached video.

ADDITIONAL INFORMATION
Output backend: DRM
Atomic Mode Setting on GPU 0: true
OpenGL vendor string: Intel
OpenGL renderer string: Mesa Intel(R) Graphics (RPL-P)
Driver: Intel
Hardware: i7-1360p (i5-i135g7 has the same issue)
Comment 1 Vlad Zahorodnii 2024-06-12 07:14:49 UTC 
Is it reproducible if KWIN_FORCE_SW_CURSOR=1 envvar is set?
Comment 2 serfreeman1337 2024-06-12 07:59:38 UTC 
No issue when KWIN_FORCE_SW_CURSOR=1 is set.
Comment 3 Vlad Zahorodnii 2024-06-12 08:12:43 UTC 
What kernel and distro do you run?
Comment 4 serfreeman1337 2024-06-12 08:22:23 UTC 
Linux 6.9.3-arch1-1 #1 SMP PREEMPT_DYNAMIC Fri, 31 May 2024 15:14:45 +0000 x86_64 GNU/Linux
ArchLinux
Wayland
Comment 5 Vlad Zahorodnii 2024-06-12 08:35:32 UTC 
Okay, that's also what I run. https://invent.kde.org/plasma/kwin/-/commit/54473f03baf4bb850683602379b7fdee185f9b3c jic
Comment 6 serfreeman1337 2024-06-12 09:19:57 UTC 
It feels like it's GTK related. I can see it with Firefox, but not with any other QT app.
Can confirm it by forcing backend for libreoffice:
SAL_USE_VCLPLUGIN=gtk3 libreoffice
SAL_USE_VCLPLUGIN=qt6 libreoffice

Jump is noticeable with SAL_USE_VCLPLUGIN=gtk3, but not with qt6 or qt5. 
Audacity with GDK_BACKEND=x11 has the same issue.

STEPS TO REPRODUCE:
1. Open libreoffice writer with gtk3:
SAL_USE_VCLPLUGIN=gtk3 libreoffice --writer
2. Write some word and start clicking on it. This selects and de-selects the word so the cursor icon changes.
3. Notice that sometimes the cursor jumps when its icon changes.
Comment 7 serfreeman1337 2025-08-11 05:11:01 UTC 
Can't reproduce the issue anymore with latest KWin 6.4.4. Looks like it got fixed.