Bug 422018

Summary:	Kwin OpenGL Graphical Glitches on Startup
Product:	[Plasma] kwin	Reporter:	kingofgamesyami
Component:	scene-opengl	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED UNMAINTAINED
Severity:	normal
Priority:	NOR
Version First Reported In:	5.18.5
Target Milestone:	---
Platform:	Manjaro
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	dmesg Xorg.0.log

Description kingofgamesyami 2020-05-24 15:52:03 UTC

SUMMARY

On my system, using OpenGL 2.0 or OpenGL 3.1 as the rendering backend introduces the following glitches during boot:

- The cursor will vanish after a short period of time with no movement
 * Upon moving the cursor after this occurrence, a chunk of the screen around the cursor will temporarily revert to the way it was displayed at the time the cursor vanished.
- The cursor may have a trail of cursors behind it (does not always occur).
- Display settings are configured wrong (my second and third monitor are sometimes not detected, or only one of the two).  NOTE: This is likely due to DisplayLink, and is probably outside the context of this ticket.

There are two workarounds I have discovered for this bug.

1. Using XRender for the Rendering backend will fix this bug (though at the cost of disabling several desktop effects).
2. Logging out (but not rebooting!) and logging back in will fix the issue.

STEPS TO REPRODUCE
1. Install Manjaro KDE on a system using Skylake Integrated Graphics (assumed - only one system tested)
2. Use OpenGL 3.1 as the rendering backend
3. Reboot

OBSERVED RESULT

The aforementioned cursor glitches (vanishing, cursor trail).

EXPECTED RESULT

No such glitches.

SOFTWARE/OS VERSIONS
Windows: N/A
macOS: N/A
Linux/KDE Plasma: Manjaro KDE stable
(available in About System)
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.70.0
Qt Version: 5.14.2

ADDITIONAL INFORMATION

inxi -Fxzc0: https://pastebin.com/m2Zrihng

Comment 1 Vlad Zahorodnii 2020-06-01 06:57:10 UTC

Hmm, it seems like an issue in xserver or something. Can you please attach /var/log/Xorg.0.log and dmesg output to the bug report after the cursor has disappeared. Also, does this bug happen when some particular application is open? or does it happen even when there is no any window open?

Comment 2 kingofgamesyami 2020-06-02 00:56:09 UTC

Created attachment 128987 [details]
dmesg

Comment 3 kingofgamesyami 2020-06-02 00:56:54 UTC

Created attachment 128988 [details]
Xorg.0.log

Comment 4 kingofgamesyami 2020-06-02 00:59:52 UTC

(In reply to Vlad Zahorodnii from comment #1)
> Hmm, it seems like an issue in xserver or something. Can you please attach
> /var/log/Xorg.0.log and dmesg output to the bug report after the cursor has
> disappeared. Also, does this bug happen when some particular application is
> open? or does it happen even when there is no any window open?

Attached.

This bug occurs immediately on startup; the desktop starts with the mouse invisible. Yakuake does have a window open but closing it does not change anything. There are also two notifications stating that Yakuake has started and NetworkManager reporting that it has established a connection.

Comment 5 kingofgamesyami 2020-06-02 01:09:53 UTC

I have also created a video of the glitch occurring (example uses chrome; note that chrome is in no way a part of triggering this glitch -- it was just the most convenient window since it has large buttons).

https://youtu.be/mwzAJ_lciYg

Comment 6 David Edmundson 2023-09-06 10:38:30 UTC

This bug was reported against an outdated version of KWin. We have made many changes since the. 
If the issue persists in newer versions can you reopen the bug report updating the version number.