Bug 470184

Summary:	Dual-monitor PC will not refresh secondary desktop after switching HDMI port in X11
Product:	[Plasma] plasmashell	Reporter:	Steve <stevmc>
Component:	Containment	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	nate, notmart, plasma-bugs-null
Priority:	NOR	Keywords:	multiscreen, wayland-only
Version First Reported In:	5.27.5
Target Milestone:	1.0
Platform:	Slackware
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Steve 2023-05-23 23:01:09 UTC

SUMMARY
***
NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***

STEPS TO REPRODUCE
1. Switching secondary monitor out temporarily from a port-replicator switch while keeping primary desktop active.
2. Switch back in secondary monitor/desktop
3.

OBSERVED RESULT
Wallpaper and Desktop menu are disabled (inactive). Right-click on secondary desktop does not invoke menu. The wallpaper that was set will disappear and turn to a black background.

EXPECTED RESULT
Wallpaper and Desktop menu should become active after a second or two of refresh time. This errant behavior does not happen on other Desktops such as XFCE and Plasma Full Wayland mode - as well as Windows OS.

SOFTWARE/OS VERSIONS
Windows:
macOS:
Linux/KDE Plasma: Slackware64 (Current)/23.04 & 5.105
(available in About System)
KDE Plasma Version: 5.27.5
KDE Frameworks Version: 5.105.0
Qt Version: 5.15.9_20230412

ADDITIONAL INFORMATION
As mentioned this is not an issue in Plasma5 full Wayland mode nor XFCE/X11. Secondary Desktop wallpaper and menu will resume/refresh after a second or two once monitor is reconnected through HDMI port replicator switch in those DE's. I have 4 computers that share the secondary monitor with a common mouse and keyboard. The brand of switch is xtremPro and is a model 4x1 USB HDMI KVM Switch 4K2K. If I use the xrandr binary in a script to temporarily switch the secondary monitor resolution I can get the secondary desktop to refresh. Below is the script:
#!/bin/bash

xrandr --output DP-2-2 --mode 1600x900
xrandr --output DP-2-2 --mode 1920x1080

Comment 1 Steve 2023-05-23 23:22:11 UTC

There is a discussion with more detail on LQ here:
https://www.linuxquestions.org/questions/showthread.php?p=6432534&posted=1#post6432534

Comment 2 Steve 2023-05-23 23:22:47 UTC

There is more detail in a discussion on LQ here:

https://www.linuxquestions.org/questions/showthread.php?p=6432534&posted=1#post6432534

Comment 3 Nate Graham 2023-05-24 17:36:21 UTC


*** This bug has been marked as a duplicate of bug 467074 ***

Comment 4 Steve 2023-05-24 18:08:04 UTC

I disagree this is a duplicate of bug 467074. The behavior might be similar but it is triggered here by a completely different mechanism. That is a  (temporary) hardware disconnection of the secondary monitor - unlike whatever the trigger is on 467074.

Comment 5 Steve 2023-05-24 19:51:13 UTC

(In reply to Steve from comment #4)
> I disagree this is a duplicate of bug 467074. The behavior might be similar
> but it is triggered here by a completely different mechanism. That is a 
> (temporary) hardware disconnection of the secondary monitor - unlike
> whatever the trigger is on 467074.

After further inspection of bug 467074 I retract the above comment as it could very well be the same issue. My apologies Nate.