Bug 507198

Summary:	Resizing tiled apps sometimes leave a gap between them (on laptop with hybrid graphics)
Product:	[Plasma] kwin	Reporter:	Mathis Paquet <mathispaquet362>
Component:	Quick Tiling	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	minor	CC:	flaviannxmbo, kdedev, mathispaquet362, nate
Priority:	NOR
Version First Reported In:	6.4.3
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Gap

Description Mathis Paquet 2025-07-18 13:45:37 UTC

SUMMARY
When resizing tiled apps (moving the separator in between them), there sometimes is a gap in between them. This seems to possibly occur with electron apps running native Wayland (such as Obsidian, but not VsCode, weirdly) and on XWayland windows. 

STEPS TO REPRODUCE
1. Open any KDE app and open Obsidian
2. Tile them on both sides of the screen
3. Resize the separator between them. Do it fast.

OBSERVED RESULT
There is sometimes a gap left between the windows

EXPECTED RESULT
There should be no gaps

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Kernel Version: 6.15.6-arch1-1 (64-bit)
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1

Comment 1 Mathis Paquet 2025-07-18 13:54:38 UTC

Created attachment 183323 [details]
Gap

Comment 2 Mathis Paquet 2025-07-18 14:54:01 UTC

This issue only occurs if my laptop is set to use hybrid (Nvidia + Intel) graphics in the BIOS. It does not happen when using dedicated GPU only.

Comment 3 TraceyC 2025-07-23 00:49:15 UTC

On Plasma 6.4.3, when I quickly move the separator, I do see the gap while moving it but not when I stop moving it. 
The laptop has a dedicated NVIDIA GPU, and an integrated Intel. In the EFI it's set to use only the NVIDIA

I see the same on a laptop running git-master with only an integrated AMD GPU.

I'll leave this open and hopefully someone else can reproduce

Comment 4 Cavalier0491 2025-10-01 15:28:18 UTC

I'm having the same issue on a hybrid intel iGPU + nvidia dGPU laptop

Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.18.0
Qt Version: 6.9.2
Kernel Version: 6.16.8-200.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i5-7300HQ CPU @ 2.50GHz
Memory: 24 GiB of RAM (23.3 GiB usable)
Graphics Processor 1: Intel® HD Graphics 630
Graphics Processor 2: NVIDIA GeForce GTX 1050 Ti
Manufacturer: ASUSTeK COMPUTER INC.
Product Name: FX502VE
System Version: 1.0