Bug 514355 - Tiles layout resetting on portrait mode monitor after system reboot
Summary: Tiles layout resetting on portrait mode monitor after system reboot
Status: RESOLVED FIXED
Alias: None
Product: kwin
Classification: Plasma
Component: Quick Tiling (other bugs)
Version First Reported In: 6.4.5
Platform: Gentoo Packages Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: multiscreen
Depends on:
Blocks:
 
Reported: 2026-01-09 00:59 UTC by pbuckston
Modified: 2026-06-04 15:47 UTC (History)
4 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In: 6.6.6
Sentry Crash Report:


Attachments

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Description pbuckston 2026-01-09 00:59:48 UTC
SUMMARY
I have two monitors connected to my system. One in landscape, one in portrait. After screen and/or system sleep, not every single time, the simple layout of "split top/bottom" is reset on the monitor in portrait mode so that the entire monitor is one large tile zone (without a split).

STEPS TO REPRODUCE
1. Sleep monitors or system.
2. Wake up system and log in.
3. Try to use previous layout to organize windows.

OBSERVED RESULT
Window snaps to and fills entire portrait monitor.

EXPECTED RESULT
Window snaps to and fills either top or bottom tile zone as configured prior to system or display sleep.

SOFTWARE/OS VERSIONS
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: yes
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.20.0
Qt Version: 6.10.1

ADDITIONAL INFORMATION
I haven't been able to reliably reproduce the issue, but I suspect the issue coincides with seeing notifications about newly detected monitors after logging back in. This has been an issue going back to at least 6.4.5.
Comment 1 Justin Zobel 2026-01-13 01:57:45 UTC
I just set my tiling zones (Super+T) to top/bottom on one monitor and 3 columns on the other, rotated my screen 90 degrees (keeping the other landscape). Then slept my PC from the lock screen, resumed and unlocked, and the tiling zones were the same. So I can't replicate this issue.

I'm on:
Operating System: Fedora Linux 43
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.17.12-300.fc43.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 3600 6-Core Processor
Memory: 32 GiB of RAM (31.3 GiB usable)
Graphics Processor: AMD Radeon RX 7600
Comment 2 pbuckston 2026-01-13 20:31:54 UTC
I found out a way to reliably reproduce the issue, on my system at least: if I reboot, rather than let the displays or system sleep like I previously reported, it resets the layout on the portrait mode monitor every time (four attempts in a row).

Misc note that may be relevant: I'm automatically logging in as my user with session Plasma (Wayland) via SDDM.
Comment 3 pbuckston 2026-01-21 17:20:18 UTC
Just wanted to note that the original issue as reported, where it occurs after a display or PC sleep, happened again, and reset of tiling zones on portrait monitor did seem to correspond to a display detection notification pop-up as I returned to the desktop environment. It's not as reproducible as just rebooting the PC, but still a (possibly separate) problem.
Comment 4 pbuckston 2026-03-17 22:16:47 UTC
Still an issue in 6.6.2.
Comment 5 pbuckston 2026-04-28 19:39:41 UTC
Still an issue in 6.6.4.

Should I start a new ticket for this because of the change in description and repro method?
Comment 6 pbuckston 2026-05-25 20:23:25 UTC
Still an issue in 6.6.5
Comment 7 Bug Janitor Service 2026-05-31 11:24:14 UTC
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/9310
Comment 8 Vlad Zahorodnii 2026-06-01 07:42:20 UTC
Git commit 9de61e188c6b583386a3734b7f51d3658b9fbf1c by Vlad Zahorodnii, on behalf of Hynek Schlindenbuch.
Committed on 01/06/2026 at 07:22.
Pushed by vladz into branch 'master'.

tiles: fix incorrect split of single tile

The bug could be reproduced like this:

- Load the 3 column custom tiling layout.
- Delete 2 of the columns.
- Split the remaining column into top/bottom.
- Reload kwin.
- There is only one tile remaining.

The issue was that the second tile was created as a sibling of the
originally split tile (i.e. 2 tiles both with the root tile as parent),
but the root tile's layout wasn't changed. So it remained horizontal and
as a result it was saved incorrectly to JSON (2 horizontal tiles with
width = 1, instead of 2 vertical tiles with height = 0.5).

When the layout was loaded from the JSON, the second tile was dropped,
because it didn't fit.
Related: bug 506622

M  +27   -0    autotests/integration/tiles_test.cpp
M  +1    -0    src/tiles/customtile.cpp

https://invent.kde.org/plasma/kwin/-/commit/9de61e188c6b583386a3734b7f51d3658b9fbf1c
Comment 9 Vlad Zahorodnii 2026-06-01 08:33:55 UTC
Git commit 04e43bd9afbb75985c3e0b9617243d9070f84d30 by Vlad Zahorodnii.
Committed on 01/06/2026 at 08:15.
Pushed by vladz into branch 'Plasma/6.7'.

tiles: fix incorrect split of single tile

The bug could be reproduced like this:

- Load the 3 column custom tiling layout.
- Delete 2 of the columns.
- Split the remaining column into top/bottom.
- Reload kwin.
- There is only one tile remaining.

The issue was that the second tile was created as a sibling of the
originally split tile (i.e. 2 tiles both with the root tile as parent),
but the root tile's layout wasn't changed. So it remained horizontal and
as a result it was saved incorrectly to JSON (2 horizontal tiles with
width = 1, instead of 2 vertical tiles with height = 0.5).

When the layout was loaded from the JSON, the second tile was dropped,
because it didn't fit.
Related: bug 506622


(cherry picked from commit 9de61e188c6b583386a3734b7f51d3658b9fbf1c)

Co-authored-by: Hynek Schlindenbuch <schlindenbuch.h@seznam.cz>

M  +27   -0    autotests/integration/tiles_test.cpp
M  +1    -0    src/tiles/customtile.cpp

https://invent.kde.org/plasma/kwin/-/commit/04e43bd9afbb75985c3e0b9617243d9070f84d30
Comment 10 Hynek Schlindenbuch 2026-06-01 20:32:18 UTC
Git commit 59dfbab76378b2b6c4df39c75ce0b75d9b1d26de by Hynek Schlindenbuch.
Committed on 01/06/2026 at 18:02.
Pushed by vladz into branch 'Plasma/6.6'.

tiles: fix incorrect split of single tile

The bug could be reproduced like this:

- Load the 3 column custom tiling layout.
- Delete 2 of the columns.
- Split the remaining column into top/bottom.
- Reload kwin.
- There is only one tile remaining.

The issue was that the second tile was created as a sibling of the
originally split tile (i.e. 2 tiles both with the root tile as parent),
but the root tile's layout wasn't changed. So it remained horizontal and
as a result it was saved incorrectly to JSON (2 horizontal tiles with
width = 1, instead of 2 vertical tiles with height = 0.5).

When the layout was loaded from the JSON, the second tile was dropped,
because it didn't fit.
Related: bug 506622

M  +27   -0    autotests/integration/tiles_test.cpp
M  +1    -0    src/tiles/customtile.cpp

https://invent.kde.org/plasma/kwin/-/commit/59dfbab76378b2b6c4df39c75ce0b75d9b1d26de