Public bug reported:
Environment:
- Ubuntu, GNOME Shell 50.1, mutter 50.1-0ubuntu2.4, Xwayland 24.1.10
- NVIDIA GeForce RTX 5070 Ti Laptop GPU, driver 595.99.02
- BIOS set to discrete-GPU-only display mode (no hybrid graphics)
- 3 monitors: eDP 2560x1600 @133%, DP-6 1920x1080 @100% (primary), DP-5
1920x1080 @100%
- experimental-features: ['scale-monitor-framebuffer',
'xwayland-native-scaling']
Steps to reproduce:
1. Run an X11 OpenGL application via Xwayland
2. Maximize or fullscreen it on a NON-primary monitor with 100% scale.
3. Try to interact with it.
Actual result:
The window output on that monitor freezes as soon as it covers the whole
monitor.
The application keeps running.
Observations:
- Works on the primary monitor (top bar overlaps -> no direct scanout).
- Works on the 133% monitor (fractional scale -> no direct scanout).
- Changing the primary monitor moves the problem to the previously-primary
monitor.
- Placing an "Always on Top" window over part of it makes it fully usable.
- MUTTER_DEBUG_PAINT=disable-direct-scanout works around it.
- Did not occur in hybrid (iGPU+dGPU) BIOS mode.
Expected result:
Direct scanout of Xwayland windows works, or falls back to compositing, without
freezing.
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: mutter (not installed)
ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14
Uname: Linux 7.0.0-38-generic x86_64
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Oct 19 11:36:20 2026
InstallationDate: Installed on 2026-10-01 (18 days ago)
InstallationMedia: Ubuntu 26.04.1 LTS "Resolute Raccoon" - Release amd64
(20260826)
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: mutter
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: mutter (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
--
You received this bug notification because you are a member of Ubuntu
Desktop Bugs, which is subscribed to mutter in Ubuntu.
https://bugs.launchpad.net/bugs/2171397
Title:
Xwayland window freezes when direct-scanned-out on NVIDIA (discrete-
only mode)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2171397/+subscriptions
--
desktop-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
