Bug 493666

Summary:	Fullscreen apps stop working when Maximize Desktop Effect is enabled.
Product:	[Plasma] kwin	Reporter:	Marc <darkstar723>
Component:	effects-window-management	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	nate, nijahplays, xaver.hugl
Priority:	NOR
Version First Reported In:	6.1.5
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Marc 2024-09-26 02:41:48 UTC

SUMMARY
I believe this item is included by default. When the Maximize Desktop Effect is enabled under Window Management > Desktop effects, there are issues with apps when trying to enter fullscreen while the window is already maximized on the primary monitor. This effect presents the same way in Chromium, fullscreen games launched via Steam through proton and very consistently with video players like VLC. This looks like the Maximize/Restore animation is trying to process while the app is attempting to go fullscreen and breaking fullscreen in the process. This does not cause issues on a secondary monitor and I have not been able to reproduce this if the window is not already maximized.

Using VLC as an example, we can open a video, maximize the VLC window, then enter fullscreen. After entering fullscreen, the expected content will show for a fraction of a second and it looks like a window animation is trying to process, then the launched screen will become transparent showing whatever was behind the window, can not interact with the items in the window underneath. Moving the cursor or leaving it in this state will create cursor trails or other graphical glitches.

Disabling the maximize desktop effect resolves this issue and it can be reproduced if turned back on but when re-enabled seems to take time before it is 'broken' again.

STEPS TO REPRODUCE
1. Enable the 'Maximize' Desktop Effect in Window Management
2. Enter fullscreen with an app that is already maximized on your primary monitor.
3. The Maximize/Restore animation looks like it will try to run upon entering fullscreen and fullscreen will break resulting in graphical glitches and/or a transparent overlay without expected content.

OBSERVED RESULT
Fullscreen seems to work for a fraction of a second and then is replaced by what looks like a transparent non-interactive overlay showing the window one layer beneath. Graphical glitches occur if this window is ignored or the cursor moves.

EXPECTED RESULT
The item goes fullscreen and displays the fullscreen contents.

SOFTWARE/OS VERSIONS
KDE Plasma Version: 6.1.5
KDE Frameworks Version: 6.6.0
Qt Version: 6.7.2

ADDITIONAL INFORMATION

Comment 1 Nate Graham 2024-09-26 17:48:10 UTC

The Maximize effect is on by default, and I have to expect that we'd have a zillion bug reports about it if this were a widespread issue. I cannot reproduce any of the issues you're describing. They sound like they could be caused by buggy graphics drivers. What kind of GPU are you using? I'm using an Intel HD630 iGPU, 10th gen.

Comment 2 Marc 2024-09-27 02:04:03 UTC

(In reply to Nate Graham from comment #1)
> The Maximize effect is on by default, and I have to expect that we'd have a
> zillion bug reports about it if this were a widespread issue. I cannot
> reproduce any of the issues you're describing. They sound like they could be
> caused by buggy graphics drivers. What kind of GPU are you using? I'm using
> an Intel HD630 iGPU, 10th gen.

I am using a Radeon RX 6600.  

Someone linked me to 427920 here from 4 years ago and that has a lot of comments that sound like the same issue, but the fix there for a lot of the historical items was focused on the fullscreen effect instead or turning off VRR (which my hardware does not support and I cannot turn VRR on/off).  I'm not sure if this should be a duplicate of that original bug, but some of the people commenting on that bug recently sound like they're facing the same issues I was.

I'd agree that graphics driver interaction sounds possible, but I have so far been able to make the issue go away completely by turning off the Maximize effect alone, it went away immediately after I found an arch linux forum post suggesting that it could be an effect issue.  The other item that confuses me as far as it being a graphic driver issue is that it is only consistent when on the primary monitor and the item is already maximized, the bug triggers consistently if those things are true, but I wasn't able to reproduce it even once when they are not.  Does the restore animation attempt to process if there's not a panel on the same monitor for it to 'restore' to?

I am nowhere near an expert here though and I'm mostly just very happy that it's fixed for me.  I'm completely content just having that effect off... but if there's any other info that could be useful, I'm happy to provide it.

Comment 3 Zamundaaa 2024-09-27 12:06:30 UTC

There's a chance that https://invent.kde.org/plasma/kwin/-/merge_requests/6529 will help with this

Comment 4 nijahplays 2024-09-29 05:05:50 UTC

I am getting this as well on Fedora 40 on KDE 6.1.5

Fixed my disabling the "Maximize" effect

May be irrelivant but I am also using an AMD RX 6600 XT

Comment 5 Marc 2024-10-02 12:38:19 UTC

(In reply to nijahplays from comment #4)
> I am getting this as well on Fedora 40 on KDE 6.1.5
> 
> Fixed my disabling the "Maximize" effect
> 
> May be irrelivant but I am also using an AMD RX 6600 XT

I double checked, weirdly enough, my RX 6600 is in fact the XT version, it is a super popular card as far as AMD goes.

Comment 6 nijahplays 2024-10-07 02:35:41 UTC

Just got that bug again, this time on my laptop. Same Plasma version.

Happened when launching a Wine application using bottles. Solved by disabling the effect again.

Fedora 40 Wayland
8 × Intel® Core™ i5-10210U CPU @ 1.60GHz
Mesa Intel® UHD Graphics
LENOVO
ThinkPad X1 Carbon 7th

Comment 7 Vlad Zahorodnii 2024-10-07 09:34:40 UTC

Okay, it should be fixed in 6.2 then