Bug 353722 - background lost multi-monitor setup
Summary: background lost multi-monitor setup
Status: CLOSED DUPLICATE of bug 353975
Alias: None
Product: KScreen
Classification: Plasma
Component: common (show other bugs)
Version: 5.4.1
Platform: Fedora RPMs Linux
: NOR normal
Target Milestone: ---
Assignee: Daniel Vrátil
Depends on:
Reported: 2015-10-09 13:41 UTC by aappddeevv
Modified: 2022-09-14 02:39 UTC (History)
13 users (show)

See Also:
Latest Commit:
Version Fixed In:


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Description aappddeevv 2015-10-09 13:41:48 UTC
2 monitors: laptop and external connected via mini-display port. I am running F22 on MBP 8,11. I typically run with 4 virtual desktops but even with one desktop, I have the same problem as described below.

It is often the case when I start the computer or when I attach the monitor, I need to manually set the external to turn on. I use the Display Configuration in the SystemSettings app.

Almost all of the time, when I activate the external monitor, the laptop monitor goes black and does not display the background. However, the laptop monitor does still continue to work and I can drag windows to it.

I've been unable to reliable reproduce the scenario where this always happens. Sometimes, if I sleep the laptop and play around with the external settings I get it to work and both monitors have backgrounds and content.

It is always the case that at some point, if I try to use kscreen too much, I get into a situation where I am no longer able to click on the background of the external monitor (where a background does exist) and activate any of the widgets or click on the system panel.

All of the time, when I set the laptop screen to be the primary output, the system panel attaches to the external screen as if the laptop screen does not exist. It is often the case that when I select the laptop to be the primary output, the screen config and clickability of the screen becomes worse and I often have to reboot after awhile. I have also seen the case where if I select the laptop screen to be the primary screen and activate the external monitor, the system panel is stuck in the middle of the external screen exactly where it would be if it was actually on the laptop monitor.

Reproducible: Always

Steps to Reproduce:
1. attach external monitor
2. use kscreen to activate the external screen

Actual Results:  
The laptop screen goes blank but can still have a window placed on it by dragging from the external monitor. The laptop screen is still enabled in kscreen of course. 

Expected Results:  
The laptop screen should have a background on it.
Comment 1 Olivier van der Toorn 2015-10-20 10:55:38 UTC
I see this bug from time to time too. Not really sure what triggers it.
For me running 'kquitapp plasmashell; kstart plasmashell' fixes the problem, but that is a bit of a dirty work around.
Comment 2 aappddeevv 2015-10-22 20:43:54 UTC
That's what I have been doing as well.

It's possibly exacerbated by multiple screens and applications that go full screen. But so far just multiple screens seems to trigger the issue.
Comment 3 aappddeevv 2015-10-23 20:00:05 UTC
I should say that restarting plasmashell actually does not cause kscreen to properly activivate the laptop screen. It's still black. But I do get back a desktop that I can click on and a working system panel.
Comment 4 Artem E 2016-03-21 08:42:13 UTC
I am having a similar issue. I have plasma 5.5 and apps 15.12.3 installed and can reliably trigger this sort of behavior (many different screen switching bugs in random order, really) using xrandr. How can I help?
Comment 5 Roman Zimmermann 2016-07-19 10:32:30 UTC
I can reproduce this behavior on plasma 5.7.1:
* background on primary/laptop screen and no right click menu
* panel displayed on non-primary screen
* everything returns to normal when I execute "kquitapp plasmashell; kstart plasmashell".
Comment 6 Enno Köster 2016-08-17 06:59:28 UTC
Confirmed with plasmashell and kwin 5.7.3, frameworks 5.24.0 (and a lot of previous versions of them) on Arch

I saw the background of my secondary monitor die quite often. After going black lots of other things are displayed on it instead, for example small tooltips (stretched to the whole screen) or other windows. Today I saw it happen when I closed Dolphin on the primary monitor.

I would expect the problem to come from kwin because I have seen the same effect happen to the contents of other windows like the telepathy contact list or the quassel-client. Maximizing the window in question made the problem go away. I guess the plasmashell background could be repaired like that aswell if one could change the size of it in that moment.
Comment 7 Martin Insulander 2017-06-22 09:50:07 UTC
I also have problems when switching between displays.

In my case I have a laptop connected to two external monitors in a docking station.
Disconnecting the laptop and then reconnect it causes the second monitor to go back to default, 
loosing widgets and background settings.

I found that there is a small config change with the monitors in the plasmashellrc file. When ok it
looks like
2=DELL U2412M/0FFXD46N57CS

And here is the diff after disconnecting and connecting the laptop.
~/.config diff /home/.snapshots/3452/snapshot/martin/.config/plasmashellrc plasmashellrc
< 1=DP-2-2
> 1=:0.0
> 6=DP-2-2
> 7=eDP-1

A quick fix to get back widgets, background and settings in a running session is to revert the plasmashellrc file and run
killall plasmashell; kstart plasmashell

Best regards from Martin Insulander

Debian testing
KDE framework 5.28.0
Qt 5.7.1
kwin-x11 5.8.6-1
Comment 8 Mika Norén 2020-05-11 04:20:03 UTC
This is still a problem today.
I have the same problems as described.
It's not just the background. All containers that resides on any monitor that isn't the primary screen get randomized each boot.
Comment 9 Martin Insulander 2020-05-11 07:22:38 UTC
@Mika, what version?
I am now running 18.4 and recently 17.5 on X11 and I have almost no issue with this (some small tests on wayland and it seemed to work too, but it is not ready for my work routines yet).

I have though the issue not all monitors are detected or woken up. But I think it is due to X or the intel drivers. Switching to tty (ctrl-alt-F2) wait and then back (usually ctrl-alt-F7) gets the monitors working.

I have had some rare weird cases, so it isn't perfect. But very close to.
Comment 10 Mika Norén 2020-05-11 23:52:48 UTC
Distribution: Arch Linux.
KDE Frameworks 5.70.0
Qt 5.14.2 (built against 5.14.2)
plasmashell 5.18.5

As previously mentioned, I also have to manually edit ~/.config/plasmashellrc, section [ScreenConnectors].
I there simply delete the mysterious :0.0 that pops up from seemingly nowhere.
The number it's assigned to may is random. sometimes it's right in between the other displayport screens:


Sometimes it appears at the end:


Sometimes it doesn't appear at all (As it should be):


I manually edit the mentioned file and remove the :0.0 and rearrange the numbering order of the other displayports. Then I restart plasmashell and I get back to where it's supposed to be.
After the next sleep/hibernation/reboot it might or might not get randomized again. Then I have to rinse and repeat the procedure.
Comment 11 Mika Norén 2020-10-12 06:33:02 UTC
There seem to be a patch available that fixes this. I suspect it's now just a matter of time before we'll see it.

Thread about it: https://www.mail-archive.com/kde-bugs-dist@kde.org/msg484655.html
The patch in question: https://invent.kde.org/genpfault/plasma-workspace/commit/181fc5746e9b4aaf491a90e76e770df866d880ad
Comment 12 Georg Grabler 2021-03-23 22:18:22 UTC
I'm still experiencing this on plasma 5.21.2 in Solus, after almost every reboot the 2nd screen (HDMI-A-0) goes to have a black background and not being responsive in a sense of clicks, you can drag windows there though.


plasmashell --replace ends up resetting it properly and that always works for me, but is no more than a workaround.

I tried to apply the above patches to 5.21.2 (https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/352, especially the one of @jacajack from two month ago), but that fails already, so no need to try against master.

The issue persists though.
Comment 13 Mika Norén 2021-12-02 14:29:55 UTC
Wanted to add that this is still a problem.
There have been no changes whatsoever with the last updates.
I tried using wayland, but that is even worse.

Operating System: Arch Linux
KDE Plasma Version: 5.23.3
KDE Frameworks Version: 5.88.0
Qt Version: 5.15.2
Kernel Version: 5.15.5-arch1-1 (64-bit)
Graphics Platform: X11
Comment 14 Ben 2022-08-02 00:03:12 UTC
I have this issue as well

If i boot the Desktop PC up with my main (Primary Monitor - HDMI) on, and my DVI connected monitor is OFF then my Main (Primary)
monitor has a black background - despite me having a selected background wallpaper

If i then turn my DVI connected second monitor on, it too has a black desktop background despite having a chosen desktop wallpaper

Then i occasionally get a few things happening

*Pressing the application menu meta key often displays the menu in the DVI connected monitor in the bottom left-hand corner
the exact place where it is meant to be displayed on my Primary HDMI connected monitor

*If i turn my main Primary monitor off, then the windows that are open on it will often suddenly appear on the second external DVI connected monitor

OS: Opensuse tumbleweed


Operating System: openSUSE Tumbleweed 20220729
KDE Plasma Version: 5.25.3
KDE Frameworks Version: 5.96.0
Qt Version: 5.15.5
Kernel Version: 5.18.11-1-default (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i5-3570K CPU @ 3.40GHz
Memory: 15.5 GiB of RAM
Graphics Processor: AMD PITCAIRN
Comment 15 Zamundaaa 2022-08-02 10:10:07 UTC

*** This bug has been marked as a duplicate of bug 353975 ***
Comment 16 Ben 2022-09-10 09:22:31 UTC
Despite the latest GPU firmware updates, kde plasma wayland still has issues with multiple screen
When i boot up my PC, i often still get a black screen when my primary monitor is the only one turned on
if i then click in any windows of any app the background desktop wall paper then correctly shows
The desktop background will alternate between black and wall paper depending on if i click anywhere on the desktop screen or in an app window
After x number of seconds, the background wall paper will correctly just 'show'

Operating System: openSUSE Tumbleweed 20220907
KDE Plasma Version: 5.25.4
KDE Frameworks Version: 5.97.0
Qt Version: 5.15.5
Kernel Version: 5.19.7-1-default (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i5-3570K CPU @ 3.40GHz
Memory: 15.5 GiB of RAM
Graphics Processor: AMD PITCAIRN
Comment 17 Nate Graham 2022-09-14 02:38:44 UTC

*** This bug has been marked as a duplicate of bug 353975 ***