Another occurrence today (2026-08-21), same signature as before. Last clean page-flip on the external CRTC (145) at 18:31:35, then zero commits for 14m40s while the internal panel's CRTC kept flipping normally — isolated to that output's stage-view, not a global hang.
MUTTER_DEBUG_PAINT=disable-direct-scanout was active the entire time (confirmed via /proc/<pid>/environ) and did not prevent it. New this time: caught it live, mid-freeze. `i915_display_info`/`state` in debugfs showed CRTC 145 as enable=yes, active=yes, correct mode, last framebuffer still visible — kernel/hardware fine *while* frozen, not just after. Recovery (Ctrl+Alt+F2→F3) again read "changed: no" for that CRTC. One more lead: I had MUTTER_DEBUG_TRIPLE_BUFFERING=never set for a long stretch until ~2 weeks ago, don't recall a freeze during that period. Turned it off to keep reproducing for these reports; both captured incidents happened with it back on. Re-enabled it now as a test — not proposing it as a fix (it's presumably there for frame-pacing), but if it suppresses the freeze that would point at the triple-buffering swap- chain bookkeeping in the KMS backend. ** Attachment added: "log-2026-08-21.zip" https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2162087/+attachment/5994164/+files/log-2026-08-21.zip -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2162087 Title: External monitor freezes completely (incl. cursor) on Meteor Lake iGPU, audio continues To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2162087/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
