Queued: https://launchpadlibrarian.net/796233692/mutter_46.2-1ubuntu0.24.04.9_source.changes
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/2111698 Title: [SRU] On noble with Intel Arrow Lake systems, glxgears FPS is much less than the panel refresh rate Status in OEM Priority Project: New Status in mutter package in Ubuntu: Fix Released Status in mutter source package in Noble: Fix Committed Status in mutter source package in Oracular: Won't Fix Status in mutter source package in Plucky: Fix Released Status in mutter source package in Questing: Fix Released Bug description: [ Impact ] * When running glxgears fullscreen on Intel Arrow Lake laptop, the FPS can be dropped to 2/3 of display refresh rate, which should not happen since glxgears has low workload. [ Test Plan ] * Find a laptop with Intel Arrow Lake CPU and use its integrated GPU * Enter Ubuntu Desktop, ensure nothing else is running, open terminal and run glxgears -fullscreen * The FPS of glxgears reported in the terminal should be close to display refresh rate * As a regression test, verify that an Intel system *older* than Arrow Lake achieves glxgears results close to the display refresh rate. [ Where problems could occur ] * This touches the screen refresh part of mutter in Wayland, therefore if this breaks it could affect all systems using GNOME in Wayland. [ Other Info ] * We don't have other issue reported than glxgears e.g. fullscreen gaming, however this can be an indicator to actual screen refresh issues under such config. === Original Report === [Issue] Upstream report: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13759 glxgears -fullscreen does not stick to the refresh rate of the display on Arrow Lake systems. According to upstream report, applying the following MPs can fix the issue: * https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3958 * https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3999 I've drafted a debdiff for this issue, but I'd like a review from whoever knows the internal workings of KMS. [Reproduce Steps] Ensure nothing else than terminal is running, then run `glxgears -fullscreen` on Intel Arrow Lake with integrated GPU [Expected Behavior] FPS should be close to the refresh rate of the display. [Actual Behavior] From the upstream report (with 75 Hz display): Running synchronized to the vertical refresh. The framerate should be approximately the same as the monitor refresh rate. 375 frames in 5.0 seconds = 74.992 FPS 286 frames in 5.0 seconds = 57.136 FPS 221 frames in 5.0 seconds = 44.151 FPS 220 frames in 5.0 seconds = 43.953 FPS 216 frames in 5.0 seconds = 43.157 FPS To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/2111698/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
