Bug 515627 - Desktop hangs on newer iGPU (AMD AI 340)
Summary: Desktop hangs on newer iGPU (AMD AI 340)
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: wayland-generic (other bugs)
Version First Reported In: 6.5.3
Platform: Arch Linux Linux
: NOR crash
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2026-02-06 14:39 UTC by whfich
Modified: 2026-02-08 03:34 UTC (History)
1 user (show)

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


Attachments
journalctl --user-unit plasma-kwin_wayland --boot -1 (1.60 KB, text/plain)
2026-02-07 06:01 UTC, whfich
Details
journalctl -k --boot -1 (111.30 KB, text/plain)
2026-02-07 06:02 UTC, whfich
Details

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Description whfich 2026-02-06 14:39:07 UTC
Plasma: 6.5.x
KWin: 6.5.3
Session: Wayland
GPU: AMD AI 340 (Framework laptop)
Kernel: Linux 6.18.x and lts
UEFI firmware: 3.04 and 3.05 (latest)

Description:
    session hangs after login. The hang appears in 3 forms:
        immediatly (Most common):
            only wallpaper and mouse is visible, no interaction works.
        after a few seconds (uncommon):
            desktop loads (files, icons, desktop bar,...) but no interation works.
        ~8 second span (rare):
            desktop loads and ineractions work until hang.

While the first 2 symptoms are the most common, the third one was achieved by downgrading kwin or by forcing openGL backend, but I believe it is noise since it was a consistent increase, type 1 still occurs.

In the hang state trying to escape to TTY with ctrl+alt+f2 yields a completly black screen. A second try also gave a completly frozen sddm screen with an X shaped cursor after flashing a black screen.
Thus the only escape I used is forced shutdown through power button hold.

I looked at the journal with 'journalctl -b -1' and as expected there were no warnings nor errors.
This is my strongest evidence that it is a hang.

I installed x11 session, it appears to work (went in 3 times, so it appears reliable).
Thus I believe it is wayland only.

downgrading kwin alone from 6.5.3 to 6.5.1 or 6.4.7 did not fix.
downgrading all packages to 2026/01/25 is stable (I used it for 8 days before updating).
2026/01/31 seems stable but I did observe the hang once.
beyond 2026/02/01 it is unstable.
This behavior suggests a timing or race condition related regression rather than a single deterministic change.
NOTE: The dates refer to ALA (Arch linux Archive).

On my machine The feb 1 update only involved:
    archlinux-keyring noto-fonts python-numpy python-wcwidth python-wheel yt-dlp
from which only noto-fonts stood out. But it is unrelated as excluding that package does not stop hangs.
The update from Jan 31 involves many KDE packages it is also has the earliest presence of the hang.
I wasn't able narrow it to single package due to the inconsistent nature of the bug.

If needed I will share additional diagnostics and preform the necessary experiments.
Comment 1 whfich 2026-02-06 14:46:05 UTC
I forgot to mention

the kernel flag 'nomodeset' prevents it. I've been using it with that flag between the experiments I conducted.
Comment 2 Zamundaaa 2026-02-06 20:30:54 UTC
Please reproduce the hang, and then attach the output of
> journalctl --user-unit plasma-kwin_wayland --boot 0
and
> journalctl -k --boot 0
(or "--boot -1" if you reboot in between)

If you enable ssh, you can get the logs and shut down from ssh without forcing poweroff.
Comment 3 whfich 2026-02-07 05:59:07 UTC
Steps I followed to reproduce:
    pacman -Syu
    reboot

    This was instance of the most common type of hung with only wallpaper and cursor appearing.
    While it was hanging I waited a little bit, then I pressed ctrl+alt+fn+f2 to switch to TTY to get further diagnostics. This time SDDM reappeared with an X-shaped cursor. The cursor could move, but all UI elements were unresponsive.

    I forced shutdown via power button hold.
    on next boot I appended nomodeset.
    journalctl --user-unit plasma-kwin_wayland --boot -1 > kwin.log
    journalctl -k --boot -1 > kernel.log
    sudo pacman -Syyuu --config /etc/ALApacman.conf
    reboot

For ssh I need a second device so it is little bit difficult. If it is needed later I'll use it.
I'll attach the documents shortly after this comment.
Comment 4 whfich 2026-02-07 06:01:09 UTC
Created attachment 189317 [details]
journalctl --user-unit plasma-kwin_wayland --boot -1
Comment 5 whfich 2026-02-07 06:02:09 UTC
Created attachment 189318 [details]
journalctl -k --boot -1