Thanks. Further investigation:
1. Re mutter#4839: journal since the upgrade contains 8 such errors
("Failed to post KMS update / Page flip failed / Cursor update failed:
drmModeAtomicCommit: Invalid argument"), all at two login/unlock moments
and attributed to the NVIDIA-driven externals ("No available CRTC for
monitor 'DEL DELL U2421HE'"). Sessions in which the squeeze was
reproduced repeatedly have none. drm_info while squeezed shows the eDP
primary plane scanning out a 3840x2160 FB with SRC/CRTC 3840x2160 at
1:1, identical to the working state, so this is not a KMS desync.
2. Root cause appears to be the GL max texture size. The squeeze happens
only when (logical stage width × max monitor scale) exceeds 16384 on the
Intel primary GPU. With eDP at 2.0 plus four 1920px monitors in a row
(9600 logical → 19200), the eDP is squeezed to ~16384/19200 of its
width, gnome-shell logs "Failed to create texture 2d due to size/format
constraints", and screenshots fail with the same error. Moving one
monitor below the row (7680 → 15360) removes the squeeze, and the
screenshot succeeds at 15360x4320 (= stage × 2). Predicted and confirmed
by switching layouts in one session; scale 1.0 or physical layout mode
also avoid it.
3. Re bug 1967450: no evidence of a shared cause. That bug uses the
upper-left quarter (both axes) and clears after Revert or a reboot. This
one is horizontal only, persistent, and tracks the texture-size limit
exactly.
Reported this upstream as asked in
https://gitlab.gnome.org/GNOME/mutter/-/work_items/5109
--
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/2169751
Title:
Built-in 4K eDP panel renders horizontally squeezed with stale strip
and input offset at scale 2.0 in logical layout mode (hybrid
Intel/NVIDIA)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2169751/+subscriptions
--
desktop-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
