Bug 465570

Summary:	Primary display lost wallpaper (showing black screen) after waking up in Wayland
Product:	[Plasma] plasmashell	Reporter:	P Shao <shallpion>
Component:	generic-multiscreen	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	aleixpol, nate, notmart
Priority:	NOR
Version:	5.26.5
Target Milestone:	1.0
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Attachments:	error log upon screen turning on

Description P Shao 2023-02-11 05:34:50 UTC

Created attachment 156142 [details]
error log upon screen turning on

SUMMARY
I know this is probably related to https://bugs.kde.org/show_bug.cgi?id=353975 however I feel like I cannot be certain it is ConnectorId being messed up upon screen being turned off then turned on. So I would like to report it here just in case this is another bug:

I am running on an AMD 5700xt with two identical LG 4k monitors (A and B, with A being the primary on the left side) connected through display port. I noticed that (almost 100% reliably) each time when the monitor being shut off then turned on (either manually or through inactivity), the primary (always this one) display A will lose wallpaper (showing a black desktop) and right-click does not pop up the context menu. However mouse cursor can move into this screen just fine.

Additionally, I noticed that if I set monitor B as primary and switch it to "right" side in system settings, I can no longer observe this issue.  So it likely has something to do with the screen positions and order.

~/.config/plasmashellrc
```
[ScreenConnectors]
0=DP-1
1=DP-3
```

I am also attaching the log immediately following the screen turning on. 

STEPS TO REPRODUCE
1.  turn off both screen
2.  turn on them both


OBSERVED RESULT
Primary display lost wallpaper showing blank screen (but panel is visible and operable)


EXPECTED RESULT
Showing desktop normally

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
KDE Plasma Version:  5.26.5

Comment 1 P Shao 2023-02-11 05:41:57 UTC

I want to make a correction: I just tested again by switching B into primary and now after being turned on B shows a black screen. So this issue appears only affect whichever is being set as the **primary** screen.

Comment 2 P Shao 2023-02-11 06:51:04 UTC

Also want to add that I tested again using KDE Neon unstable, version 5.27.80, using exactly the same configuration as my regular environment and I can **not** reproduce this bug in 5.27.80. So there is a high chance this bug is fixed in 5.27 and hopefully will be mitigated once my machine updates to 5.27 in a few days.

Although, I want to point out that I noticed the primary display, in 5.27, will however blink once (not instant blink, more like a fast dimming animation then back to normal) before going back to normal.

Comment 3 Nate Graham 2023-02-12 17:55:22 UTC


*** This bug has been marked as a duplicate of bug 450068 ***