Bug 514240 - Built-in screen freezes on login if adaptive sync is not set to "Always"
Summary: Built-in screen freezes on login if adaptive sync is not set to "Always"
Status: NEEDSINFO WAITINGFORINFO
Alias: None
Product: kwin
Classification: Plasma
Component: wayland-generic (other bugs)
Version First Reported In: 6.5.4
Platform: Manjaro Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2026-01-06 19:30 UTC by Johannes Gäßler
Modified: 2026-01-13 21:14 UTC (History)
1 user (show)

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


Attachments
debug logs as for DRM (1.20 MB, application/gzip)
2026-01-11 14:09 UTC, Johannes Gäßler
Details

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Description Johannes Gäßler 2026-01-06 19:30:38 UTC
SUMMARY

I am using an Asus ROG Flow Z13 laptop with a built-in screen. Using Manjaro with KDE, after I updated the system my screen would freeze upon login, though I could still hear applications opening. The freeze does not occur consistently. A fresh install of Manjaro v25 is working correctly for both KDE and XFCE, KDE breaks upon update and can be fixed by rolling the update back. Manjaro v26 can already freeze during the installation process. The problem seems to be caused specifically by adaptive sync, setting it to "Always" fixes the issue.

STEPS TO REPRODUCE
1. Start the Manjaro v26 KDE installer, the screen may freeze.
2. Install Manjaro and repeatedly log in or repeatedly launch the installer until the freeze occurs.

OBSERVED RESULT

The screen freezes, all other functionality (second screen, SSH) remains unaffected.

EXPECTED RESULT

The screen works correctly.

SOFTWARE/OS VERSIONS
Operating System: Manjaro Linux
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.18.3-arch1-2-flowx13 (64-bit) (The bug is not specific to this kernel, it also occurs with the vanilla kernel)
Graphics Platform: offscreen
Processors: 32 × AMD RYZEN AI MAX+ 395 w/ Radeon 8060S
Memory: 128 GiB of RAM (121.5 GiB usable)

ADDITIONAL INFORMATION

The screen freezes if and only if adaptive sync is not set to "Always". If a second monitor is connected during login the bug does not occur. If a second monitor is connected after the login it does not unfreeze the built-in screen but the second monitor works correctly. If the built-in screen is turned off due to inactivity and then turned on again this unfreezes the built-in screen.
Comment 1 Zamundaaa 2026-01-08 20:56:50 UTC
Please get kwin and drm debug logs for the issue. The script at https://invent.kde.org/plasma/kwin/-/wikis/Debugging/Debugging-DRM-issues should work in this case
Comment 2 Johannes Gäßler 2026-01-11 14:09:34 UTC
Created attachment 188419 [details]
debug logs as for DRM

I am for some reason no longer able to reproduce the issue for my regular account, I created a new account "test" where the issue occurs on login without any changes to the default settings.
Comment 3 Zamundaaa 2026-01-13 21:14:12 UTC
The debug log shows KWin committing updates to the screen without any problems.
Please ssh into the system while its screen looks frozen, and get the output of drm_info. Then (blindly) move the cursor to some other spot, and get the output of drm_info again. That way we can be certain about whether or not KWin is still updating the screen, or if it's a driver bug.