Bug 480407

Summary:	With NVIDIA GPU, wallpaper on one screen is all black when that screen's scale is above 100%
Product:	[Plasma] plasmashell	Reporter:	Dashon <dashonwwIII>
Component:	Containment	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	dashonwwIII, fanzhuyifan, kde, nate, notmart
Priority:	NOR	Keywords:	multiscreen, qt6
Version First Reported In:	master
Target Milestone:	1.0
Platform:	Neon
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Output of journalctl -b

Description Dashon 2024-01-27 20:45:25 UTC

SUMMARY
Hey, I was testing out Plasma 6 on Neon Unstable to see how Nvidia on Wayland would be. I have two 1440p / 165Hz monitors being driven by an nvidia rtx 3080. I tried setting the display scale to 125% as well as 150% on each monitor, but both times I would log out and then back in the left monitor would have a black screen. I can see the cursor as well as the panel. It is just the wallpaper that is missing. Right clicking the black background and trying to change the wallpaper does not help in this state. Setting the display scale back to 100% on both monitors. This brings back the wallpaper.

STEPS TO REPRODUCE
1. Open system settings and go to display.
2. Set scale for both monitors to something greater than 100%.
3. Log out and then back in.

OBSERVED RESULT
Before logging out and back in I see that the first monitor starts to overlap the second. After logging out and back in. The wallpaper on the first monitor is gone, but it is still present on the second. Another thing I noticed is that the splash screen only displays on the second monitor when logging in. It does not display on the first monitor which has its wallpaper missing.

EXPECTED RESULT
Wallpaper, splash screen, etc should be present at the correct scale.

SOFTWARE/OS VERSIONS
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 6.0.80
KDE Frameworks Version: 5.249.0
Qt Version: 6.6.1
Kernel Version: 6.5.0-15-generic (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 5800X 8-Core Processor
Memory: 62.7 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 3080/PCIe/SSE2
Manufacturer: Micro-Star International Co., Ltd.
Product Name: MS-7C95
System Version: 1.0

ADDITIONAL INFORMATION
Maybe unrelated but when I set the display scale back to 100%. It seems as if the panels take around 10 seconds to appear now.

Comment 1 fanzhuyifan 2024-01-28 03:15:14 UTC

Could you provide the output of `journalctl -b` when this happens? Thanks!

Comment 2 Dashon 2024-01-28 10:30:59 UTC

(In reply to fanzhuyifan from comment #1)
> Could you provide the output of `journalctl -b` when this happens? Thanks!

I have added a file attachment with the outputs of the  `journalctl -b` command.

Comment 3 Dashon 2024-01-28 10:31:21 UTC

Created attachment 165303 [details]
Output of journalctl -b

Comment 4 Dashon 2024-01-28 14:14:27 UTC

Hey, I have since moved my testing over to arch using the kde-unstable repo. I don't have any of the problems that I described in this bug report while testing plasma 6 with this setup. Perhaps kde neon unstable wasn't the right place for me to do my testing?

Comment 5 Nate Graham 2024-01-29 21:22:03 UTC

Maybe. If you're not able to reproduce the issue then unfortunately there's probably nothing we can do about it. so I'll close this for now.