Bug 435141 - Quartered display of KDE apps after plugging a 4k monitor (same scale and resolution as internal screen)
Summary: Quartered display of KDE apps after plugging a 4k monitor (same scale and res...
Status: RESOLVED FIXED
Alias: None
Product: kwin
Classification: Plasma
Component: multi-screen (show other bugs)
Version: 5.20.5
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-03-30 08:15 UTC by frederic.parrenin@univ-grenoble-alpes.fr
Modified: 2023-02-21 20:39 UTC (History)
3 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
.png screenshot of Dolphin after plugging the docking station (159.15 KB, image/png)
2021-03-30 08:15 UTC, frederic.parrenin@univ-grenoble-alpes.fr
Details
.png screenshot of Konsole after plugging the docking station (188.69 KB, image/png)
2021-03-30 08:17 UTC, frederic.parrenin@univ-grenoble-alpes.fr
Details
.png screenshot of Kate after plugging the docking station (399.58 KB, image/png)
2021-03-30 08:22 UTC, frederic.parrenin@univ-grenoble-alpes.fr
Details
.png screenshot of Konsole after unplugging the docking station (195.98 KB, image/png)
2021-03-31 10:59 UTC, frederic.parrenin@univ-grenoble-alpes.fr
Details
.png screenshot of Kate after unplugging the docking station (109.78 KB, image/png)
2021-03-31 11:00 UTC, frederic.parrenin@univ-grenoble-alpes.fr
Details
.png screenshot of Dolphin after unplugging the docking station (213.45 KB, image/png)
2021-03-31 11:01 UTC, frederic.parrenin@univ-grenoble-alpes.fr
Details

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Description frederic.parrenin@univ-grenoble-alpes.fr 2021-03-30 08:15:56 UTC
Created attachment 137172 [details]
.png screenshot of Dolphin after plugging the docking station

SUMMARY
I have a dell XPS13 laptop with a 4k screen, so I configured the scaling at 200%
Then I have an external 4k monitor plugged to a USB-c docking station, at 200% scaling also.
Plugging/unplugging the docking station creates artifacts in the display of the KDE apps. 

STEPS TO REPRODUCE
1. Open some KDE apps on the laptop, e.g. Dolphin, Konsole, Kate
2. Close the LID to suspend
3. Plug the USB-c docking station (with the LID closed)

OBSERVED RESULT
On the external monitor, these KDE apps display their content only on the top-left quarter of their window with a 100% scaling

EXPECTED RESULT
These KDE apps should display on their whole window at 200% scaling.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Debian Bullseye/KDE 5.20.5
(available in About System)
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
I am not sure where to report this bug, maybe it belongs to another product.
Comment 1 frederic.parrenin@univ-grenoble-alpes.fr 2021-03-30 08:17:41 UTC
Created attachment 137173 [details]
.png screenshot of Konsole after plugging the docking station
Comment 2 frederic.parrenin@univ-grenoble-alpes.fr 2021-03-30 08:22:26 UTC
Created attachment 137174 [details]
.png screenshot of Kate after plugging the docking station
Comment 3 frederic.parrenin@univ-grenoble-alpes.fr 2021-03-31 10:59:48 UTC
Created attachment 137193 [details]
.png screenshot of Konsole after unplugging the docking station

Now this is the reverse: I opened Konsole on the external monitor, and un-plugged the docking station.
Comment 4 frederic.parrenin@univ-grenoble-alpes.fr 2021-03-31 11:00:41 UTC
Created attachment 137194 [details]
.png screenshot of Kate after unplugging the docking station

Same with Kate.
Notice that some UI elements are scaled correctly, while other are not.
Comment 5 frederic.parrenin@univ-grenoble-alpes.fr 2021-03-31 11:01:21 UTC
Created attachment 137195 [details]
.png screenshot of Dolphin after unplugging the docking station

Same with Dolphin.
Comment 6 Nate Graham 2021-03-31 17:58:06 UTC
Quick question: did you restart the computer (or log out and back in again) after setting the system to 200% scale?
Comment 7 frederic.parrenin@univ-grenoble-alpes.fr 2021-03-31 18:41:19 UTC
Yes, of course I did restart.
Comment 8 frederic.parrenin@univ-grenoble-alpes.fr 2021-10-07 11:10:44 UTC
Some news about this bug.
It still happens to me.
But I realized that it only happens when I use my Usb-c docking station (Dell DS-1000).
If I connect the monitor directly from the laptop using HDMI, it does not happen.
I would be happy if somebody can do something about it since it is annoying.
Thanks.
Comment 9 frederic.parrenin@univ-grenoble-alpes.fr 2021-11-25 19:09:30 UTC
This bug is still present in plasma 5.23.3.
Comment 10 frederic.parrenin@univ-grenoble-alpes.fr 2022-02-24 15:26:30 UTC
I can report that I do not experience this bug anymore.
I re-installed my system and I am now using Plasma 5.23.5.
So I don't know if this is the re-install or the new version of Plasma that fixed the problem.
Comment 11 frederic.parrenin@univ-grenoble-alpes.fr 2022-07-19 09:45:42 UTC
Maybe it is possible to close this bug now, since I do not experience it anymore.
Comment 12 David Edmundson 2022-07-19 09:46:34 UTC
A patch landed into Qt
Comment 13 frederic.parrenin@univ-grenoble-alpes.fr 2022-09-12 14:16:30 UTC
Oh no, I got this bug again today, with 5.25.4.
Comment 14 frederic.parrenin@univ-grenoble-alpes.fr 2023-02-21 10:05:22 UTC
I am now using Wayland and I never experienced this bug on Wayland.
Comment 15 Nate Graham 2023-02-21 20:39:03 UTC
I guess this can be FIXED USEWAYLAND :)