Hi Daniel,

I have a critical update regarding the i915 Wayland crashes. I have
managed to find a 100% reproducible trigger for the hard lockup, and I
also discovered a severe UX bug in Plymouth that occurs immediately
after this crash.

Environment:

Hardware: ASUS Zenbook UX331UA (Intel graphics)

OS/Kernels tested: Ubuntu 26.04, kernels 7.0.0-15-generic and the latest
7.0.0-22-generic

Session: Wayland

Bug 1: Reproducible Hard Lockup (GTK / Wayland / i915 regression)
The regression is still fully present in the new 7.0.0-22 kernel. The system 
suffers a hard lockup exactly at the moment specific GTK applications trigger a 
UI change (such as opening a save dialog or rendering a download completion 
notification).

100% Reproducible triggers:

Firefox: Downloading and saving a PDF file. The system locks up the
exact moment the download finishes and the UI attempts to update.

Remmina: Exporting to PDF.

Thunderbird: Launching the app (happened frequently, though might be
partially mitigated in recent TB updates).

The Crucial Clue: Google Chrome works perfectly and never crashes. It
can download files and run for hours without issues. This strongly
suggests the bug is strictly tied to how native GTK interacts with
Wayland and the i915 driver. Chrome's Aura/Ozone engine bypasses the
faulty calls entirely.

Bug 2: LUKS / Plymouth Alt key trapping after the crash
After the system hard-reboots from the crash mentioned above, the LUKS 
decryption screen (Plymouth) behaves erratically regarding keyboard input.

The Right Alt (AltGr) key is intercepted by Plymouth and acts as a
display switch.

Pressing Right Alt + X or Right Alt + 3 (which is required to type the #
character on a CZ keyboard layout) does not output the character into
the password field. Instead, it forcefully switches Plymouth to the raw
text tty console (and back to GUI on the next press).

Result: It becomes physically impossible to unlock the encrypted drive
if the password contains characters requiring the AltGr modifier. The
only workaround is to forcefully power off the machine and do a cold
boot, after which Plymouth behaves normally and accepts the # character.

Let me know if you need any specific logs, though the hard lockup
happens so fast that journalctl usually doesn't have time to flush the
exact crash trace to the disk.

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https://bugs.launchpad.net/bugs/2152124

Title:
  Sudden loss of session (back to login/initramfs screen)

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