Bug 413109 - After I change the screen resolution on Wayland, Kscreen shows the initial resolution on reopening
Summary: After I change the screen resolution on Wayland, Kscreen shows the initial re...
Status: RESOLVED FIXED
Alias: None
Product: systemsettings
Classification: Applications
Component: kcm_kscreen (show other bugs)
Version: 5.19.90
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: kscreen-bugs-null@kde.org
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-10-17 19:11 UTC by Patrick Silva
Modified: 2020-11-03 15:36 UTC (History)
5 users (show)

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


Attachments
screenshot (89.81 KB, image/png)
2019-10-17 19:30 UTC, Patrick Silva
Details

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Description Patrick Silva 2019-10-17 19:11:17 UTC
STEPS TO REPRODUCE
1. start Wayland session
2. open system settings > display and monitor
3. change the screen resolution from 1920x1080 to 1280x720 (the change is successful and "Resolution" dropdown shows 1280x720 , as expected)
4. reopen system settings > display and monitor

OBSERVED RESULT
"Resolution" dropdown shows 1920x1080 instead of 1280x720 

EXPECTED RESULT
"Resolution" dropdown always shows the current screen resolution

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux
(available in About System)
KDE Plasma Version:  5.17
KDE Frameworks Version: 5.63
Qt Version: 5.13.1
Comment 1 Patrick Silva 2019-10-17 19:30:03 UTC
Created attachment 123287 [details]
screenshot

This issue does not occur on X11.
The area above "Resolution" dropdown also shows 1920x1080 instead of 1280x720.
I'm attaching a screenshot.
Comment 2 Patrick Silva 2020-01-27 14:39:32 UTC
cannot reproduce with Plasma 5.18 beta.

Operating System: Arch Linux 
KDE Plasma Version: 5.17.90
KDE Frameworks Version: 5.66.0
Qt Version: 5.14.1
Comment 3 Roman Gilg 2020-01-27 15:04:31 UTC
Thanks for update!
Comment 4 Patrick Silva 2020-02-29 18:13:04 UTC
I can reproduce this bug again.

1. start Wayland session with your monitor set to 1920x1080 resolution, refresh rate 60hz
2. open system settings > display and monitor
3. set resolution to 1280x720, leave refresh rate as 60hz
4. click on 'Apply' button (the changes are applied as expected) and close system settings
5. reopen system settings > display and monitor: notice that resolution dropdown shows "1920x1080"
instead of "1280x720"
6. select 1280x720 resolution (notice that refresh rate changed itself to 50hz),
select 60hz refresh rate, click on "Apply" button (apparently nothing changes) and close system settings
7. reopen system settings > display and monitor (now the kcm shows 1280x720 resolution
and refresh rate 60hz, as expected), set resolution to 1920x1080 and refresh rate to 60hz (the changes are correctly applied)
8. Now restart Wayland session (we can notice wrong - 1280x720 - screen resolution immediately after login) and open system settings > display and monitor: screen resolution is 1280x720 and refresh rate 60hz instead of 1920x1080 and 60hz as configured in the step 7.

If I set 1920x1080 and 60hz, these settings are correctly applied but the screen resolution will be 1280x720 and refresh rate 60hz again after relogin. The only way to make kscreen remember 1920x1080 and 60hz settings again is deleting files located in /home/my_username/.local/share/kscreen/

Operating System: Arch Linux 
KDE Plasma Version: 5.18.2
KDE Frameworks Version: 5.67.0
Qt Version: 5.14.1
Comment 5 magiblot 2020-05-04 21:07:08 UTC
I can reproduce what Patrick describes in comment #4 (steps 7 and 8) every time. Not all resolutions are affected by this issue. I am using a laptop connected to an external monitor, and the lid is always closed so my settings are to only use the external display. In my case, 1280x960 and 1680x1050 are preserved after restarting the Plasma Wayland session, while 1920x1080 and 1600x1200 are not (the last of 1280x960 or 1680x1050 that had been previously set is used instead). There are obviously more resolutions but I haven't tried them.

I remember everything worked fine until I once changed my resolution from 1920x1080 to something else for an experiment. Plasma Wayland has never started again at a resolution of 1920x1080 since then, even though I change the settings every single time.

There's an exception to this -- if I start Plasma the following way:

> QT_QPA_PLATFORM=xcb startplasma-wayland
Then Kscreen is an Xwayland client and cannot change the screen resolution. In this case the monitor resolution is kept at 1920x1080 (with the drawback that the laptop screen is enabled and I have to disable it manually every time).

Regarding the directories pointed out by Patrick Silva, in ~/.local/share/kscreen/ I cannot find a Wayland setting (that is, a file without 'xrandr' nor 'XWAYLAND' in the display's names) for 1920x1080, but there is one for 1280x960. The same goes for ~/.local/share/kscreen/outputs.

Operating System: Arch Linux 
KDE Plasma Version: 5.18.4
KDE Frameworks Version: 5.69.0
Qt Version: 5.14.2
Kernel Version: 5.6.8-arch1-1
OS Type: 64-bit
Processors: 4 × Intel® Core™ i5-6200U CPU @ 2.30GHz
Memory: 11,6 GiB of RAM
Comment 6 magiblot 2020-05-04 21:18:20 UTC
1920x1080 is again my default resolution after deleting the files in ~/.local/share/kscreen/ and ~/.local/share/kscreen/outputs mentioning the undesired resolution (1280x960). There was just one of such files in each of the two directories, and in both cases it was also the most recently modified file.
Comment 7 Benjamin Port 2020-11-03 14:54:43 UTC
I cannot reproduce it, Partick can you still reproduce it ?
Comment 8 Patrick Silva 2020-11-03 15:36:50 UTC
(In reply to Benjamin Port from comment #7)
> Partick can you still reproduce it ?

No. \o/

Operating System: Arch Linux
KDE Plasma Version: 5.20.2
KDE Frameworks Version: 5.75.0
Qt Version: 5.15.1