Public bug reported: [ Impact ] * Automatic screen rotation does not work at all on affected tablets. When the user turns the tablet, the screen stays in the same orientation.
* The same hardware rotates correctly on Ubuntu 24.04 (mutter 46.2). On some tablets and convertibles, the accelerometer comes from the Intel Sensor Hub (ISH) through iio-sensor-proxy. On these machines the sensor appears *late* — the GNOME session is already in tablet mode before the accelerometer is ready. In mutter 50 this ordering breaks an internal inhibit/uninhibit counter in the orientation manager. `update_panel_orientation_managed()` calls `uninhibit_tracking()` first, before the matching `inhibit` is pushed, so `inhibited_count` goes down to -1. The code that claims the sensor only runs when `inhibited_count == 0`, so mutter never claims the accelerometer and the screen never rotates. The problem is completely silent. Stock mutter prints no warning and no error. For the user, auto-rotate just does nothing when the tablet is turned, even though iio-sensor-proxy is working, the panel is orientation-managed, tablet mode is on, and orientation lock is off. [ Test Plan ] Use an affected device (a tablet/convertible with an Intel ISH accelerometer) on Wayland GNOME session. 1. Enable Auto Rotate in the system settings menu. 2. Physically rotate the tablet 90°. 3. Read the current transform: `gdctl show | grep Transform` Without the fix: the transform stays `normal` no matter how you turn the tablet. The screen never rotates, and nothing is logged. With the fix: the transform follows the physical orientation (`normal` ↔ `90` / `180` / `270`) and the screen rotates. [ Where problems could occur ] TBD [ Other info ] - Upstream issue: https://gitlab.gnome.org/GNOME/mutter/-/issues/4350 - Upstream fix (merge request): https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4962 — "backends/monitor-manager: Fix auto-rotate on phones without tablet mode switch" - MR!4962 was verified to fix the issue. ** Affects: mutter (Ubuntu) Importance: Undecided Status: New ** Summary changed: - auto-rotate fails on tablets whose accelerometer appears late + [Draft]auto-rotate fails on tablets whose accelerometer appears late ** Summary changed: - [Draft]auto-rotate fails on tablets whose accelerometer appears late + [Draft] auto-rotate fails on tablets whose accelerometer appears late -- 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/2161055 Title: [Draft] auto-rotate fails on tablets whose accelerometer appears late To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2161055/+subscriptions -- desktop-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
