Bug 465993

Summary:	KDE 5.27 Visual Ghosting (Wayland)
Product:	[Plasma] kwin	Reporter:	homelessdefragger
Component:	wayland-generic	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	kdeuser151516, nate, oxygelfr
Priority:	NOR
Version:	5.27.0
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description homelessdefragger 2023-02-18 11:53:50 UTC

Certain software (Notably dolphin and KDENLive) on Wayland have weird ghosting/transparency issue.


STEPS TO REPRODUCE
1. Opening one of the mentioned software.

OBSERVED RESULT

Ghosting/Transparency, while having weird flickering effect

EXPECTED RESULT

Normal functionality.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Arch Linux
(available in About System)
KDE Plasma Version: 5.27.0
KDE Frameworks Version: 5.103.0
Qt Version:  5.15.8

Video showcasing the visual issues: https://streamable.com/4ap83y

Comment 1 user151516 2023-02-18 18:53:13 UTC

I experience similar - weird ghosting issues in the alt-tab application switcher. The view that lets you see all windows on all desktops similar to Mac (I think it's called "overview") also has lots of strange ghosting.

Linux/KDE Plasma: Arch Linux
(available in About System)
KDE Plasma Version: 5.27.0
KDE Frameworks Version: 5.103.0
Qt Version:  5.15.8

Comment 2 user151516 2023-02-20 00:46:18 UTC

Aha. my issues with ghosting (and a few other issues) went away after switching the rendering backend from "software" to "automatic" in the menu spawned by this command:

`kcmshell5 qtquicksettings`

Not sure how it ever got set to software rendering, but this has fixed many bugs for me ranging from missing widet thumbnails, broken sysmonitor graphs, and broken titlebars (the last one only happened under wayland). My ghosting issues are all resolved now it seems...

Comment 3 homelessdefragger 2023-02-20 13:08:51 UTC

(In reply to Evan from comment #2)
> Aha. my issues with ghosting (and a few other issues) went away after
> switching the rendering backend from "software" to "automatic" in the menu
> spawned by this command:
> 
> `kcmshell5 qtquicksettings`
> 
> Not sure how it ever got set to software rendering, but this has fixed many
> bugs for me ranging from missing widet thumbnails, broken sysmonitor graphs,
> and broken titlebars (the last one only happened under wayland). My ghosting
> issues are all resolved now it seems...

Strange, it's "Automatic" for me, yet it still occurs... I'm not sure if it's KDE or Wayland breaking this for me. I should try on X11.

Comment 4 Oxygel 2023-02-21 22:17:43 UTC

(In reply to homelessdefragger from comment #3)
> (In reply to Evan from comment #2)
> > Aha. my issues with ghosting (and a few other issues) went away after
> > switching the rendering backend from "software" to "automatic" in the menu
> > spawned by this command:
> > 
> > `kcmshell5 qtquicksettings`
> > 
> > Not sure how it ever got set to software rendering, but this has fixed many
> > bugs for me ranging from missing widet thumbnails, broken sysmonitor graphs,
> > and broken titlebars (the last one only happened under wayland). My ghosting
> > issues are all resolved now it seems...
> 
> Strange, it's "Automatic" for me, yet it still occurs... I'm not sure if
> it's KDE or Wayland breaking this for me. I should try on X11.

I can confirm the same behaviour for me