Bug 431525 - KScreenlocker crops screen on hidpi after monitor connection
Summary: KScreenlocker crops screen on hidpi after monitor connection
Status: RESOLVED NOT A BUG
Alias: None
Product: kwin
Classification: Plasma
Component: general (show other bugs)
Version: unspecified
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-01-13 04:14 UTC by Xu Zhao
Modified: 2021-01-21 16:05 UTC (History)
2 users (show)

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

Attachments
The monitor shows only the top left quarter of the entire lock screen. (62.41 KB, image/jpeg)
2021-01-13 04:14 UTC, Xu Zhao 		Details
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Description Xu Zhao 2021-01-13 04:14:48 UTC 
Created attachment 134798 [details]
The monitor shows only the top left quarter of the entire lock screen.

SUMMARY

I am using kscreenlocker 5.20.5 on 4K monitor (DELL U2720Q).
Scaling Factor is 2.0.
Kernel 5.10.5, Display Card Radeon 6800XT, Driver amdgpu.

STEPS TO REPRODUCE
1. Lock the screen
2. Disconnect monitor
3. Reconnect monitor

OBSERVED RESULT

The monitor only shows top left quarter of the screen. The rest part is chopped.

EXPECTED RESULT

Show the entire screen.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.20.5
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.77.0
Qt Version: 5.15.2

openSUSE Tumbleweed 20210105

ADDITIONAL INFORMATION

After pressing Ctrl-Alt-F1 to switch to TTY, then press Ctrl-Alt-F7 to switch back to lockscreen, the problem is fixed.
Comment 1 Nate Graham 2021-01-13 19:37:12 UTC 
Seems like a graphics issue. Wayland or X11?
Comment 2 Xu Zhao 2021-01-13 19:41:16 UTC 
(In reply to Nate Graham from comment #1)
> Seems like a graphics issue. Wayland or X11?

Thanks for the reply! I am using X11. I have tried adding 90-monitor.conf in /etc/X11/xorg.conf.d: 

Section "Monitor"
        Identifier      "<default monitor>"
        DisplaySize     345 194 # in millimeters
EndSection

But it doesn't work.
Comment 3 Nate Graham 2021-01-13 19:51:31 UTC 
Thanks for the info.
Comment 4 Xu Zhao 2021-01-21 16:05:32 UTC 
The problem disappears after I switch from HDMI to DisplayPort. Closed.