Bug 478563

Summary: Ghosting/Flickering Nvidia wayland - Introduced in Plasma 6
Product: [Plasma] kwin Reporter: kodatarule
Component: wayland-genericAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED FIXED    
Severity: major CC: nate, vlad.zahorodnii, xaver.hugl
Priority: NOR Keywords: qt6
Version First Reported In: 5.90.0   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: https://invent.kde.org/plasma/kwin/-/commit/51ff2e4c32b6e061992b5a6ae2ed126110a3b628 Version Fixed In: 6.0
Sentry Crash Report:

Description kodatarule 2023-12-15 16:00:44 UTC 
SUMMARY
There seems to be some unusual ghosting/flickering even in native wayland apps since plasma 6 update, note this does not happen on plasma 5.(Nvidia)


STEPS TO REPRODUCE
1. Just setup a widget like the CPU Core Usage or Hard Disk activity, after a little bit you may notice frame duplication/ghosting/artifacting

OBSERVED RESULT
ghosting of frames/artifacting/sometimes flicker

EXPECTED RESULT
To be as on Plasma 5, smooth on wayland apps and mostly fine xwayland with the explicit sync patched in(xorgproto, wayland-protocols and xorg-xwayland packages)

SOFTWARE/OS VERSIONS
Operating System: EndeavourOS 
KDE Plasma Version: 5.90.0
KDE Frameworks Version: 5.246.0
Qt Version: 6.6.1
Kernel Version: 6.6.6-1-cachyos (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 5800X3D 8-Core Processor
Memory: 31,2 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 3090/PCIe/SSE2
Nvidia driver version: 545.29.06 - note this driver does introduce it's own issues, but what is observed on the desktop can also be observed on 535 which did not exhibit such problems on native wayland apps, nor on xwayland with the explicit sync patches on Plasma 5. There is some change in Plasma 6/QT6 which affects this.