** Description changed: [ Impact ] Fullscreen direct scanout is not used if you enable the hidden experimental VRR feature in Mutter 46. [ Test Plan ] 0. Find a monitor that is VRR capable. - 1. Set MUTTER_DEBUG=kms in /etc/environment - 2. Enable VRR (TODO: need to relearn all the steps required) + 1. Set CLUTTER_PAINT=damage-region in /etc/environment + 2. gsettings set org.gnome.mutter experimental-features '["variable-refresh-rate"]' 3. Reboot. 4. Log into a Wayland session. - 5. Open Google Chrome, start an animation like https://www.vsynctester.com/ and make it full screen (F11). - 6. journalctl -f /usr/bin/gnome-shell | grep Post - 7. Verify the "Post" messages you see mention direct scan out and not "composite". + 5. Don't panic. The screen is meant to turn red whenever something changes. + 6. In Settings > Display verify that variable refresh rate is detected and enabled. + 7. Open a web browser, start an animation like https://www.vsynctester.com/ + 8. Press F11 to make it full screen. + 9. Verify the screen has now stopped being red. + 10. Press F11 again to exit full screen. + 11. Verify the screen has gone red again. [ Where problems could occur ] Since the fix affects the runtime decision of whether to allow triple buffering or stay double buffering, the main risk is that triple buffering wouldn't be used in some situation where we would rather have it to maintain a smoother frame rate. [ Other Info ] First reported upstream in: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1441#note_2062222 We DO NOT recommend enabling the VRR feature anyway because it is still buggy (bug 2066080)
** Description changed: [ Impact ] Fullscreen direct scanout is not used if you enable the hidden experimental VRR feature in Mutter 46. [ Test Plan ] 0. Find a monitor that is VRR capable. 1. Set CLUTTER_PAINT=damage-region in /etc/environment 2. gsettings set org.gnome.mutter experimental-features '["variable-refresh-rate"]' 3. Reboot. 4. Log into a Wayland session. 5. Don't panic. The screen is meant to turn red whenever something changes. 6. In Settings > Display verify that variable refresh rate is detected and enabled. - 7. Open a web browser, start an animation like https://www.vsynctester.com/ + 7. Open Google Chrome (Firefox won't work) and start an animation like https://www.vsynctester.com/ 8. Press F11 to make it full screen. 9. Verify the screen has now stopped being red. 10. Press F11 again to exit full screen. 11. Verify the screen has gone red again. [ Where problems could occur ] Since the fix affects the runtime decision of whether to allow triple buffering or stay double buffering, the main risk is that triple buffering wouldn't be used in some situation where we would rather have it to maintain a smoother frame rate. [ Other Info ] First reported upstream in: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1441#note_2062222 We DO NOT recommend enabling the VRR feature anyway because it is still buggy (bug 2066080) ** Description changed: [ Impact ] Fullscreen direct scanout is not used if you enable the hidden experimental VRR feature in Mutter 46. [ Test Plan ] 0. Find a monitor that is VRR capable. 1. Set CLUTTER_PAINT=damage-region in /etc/environment 2. gsettings set org.gnome.mutter experimental-features '["variable-refresh-rate"]' 3. Reboot. 4. Log into a Wayland session. 5. Don't panic. The screen is meant to turn red whenever something changes. 6. In Settings > Display verify that variable refresh rate is detected and enabled. 7. Open Google Chrome (Firefox won't work) and start an animation like https://www.vsynctester.com/ 8. Press F11 to make it full screen. 9. Verify the screen has now stopped being red. 10. Press F11 again to exit full screen. 11. Verify the screen has gone red again. + If the screen went black at the end, don't panic. That's a separate bug + 2066080. + [ Where problems could occur ] Since the fix affects the runtime decision of whether to allow triple buffering or stay double buffering, the main risk is that triple buffering wouldn't be used in some situation where we would rather have it to maintain a smoother frame rate. [ Other Info ] First reported upstream in: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1441#note_2062222 We DO NOT recommend enabling the VRR feature anyway because it is still buggy (bug 2066080) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2070438 Title: Fullscreen direct scanout is not used if you enable the hidden experimental VRR feature in Mutter 46 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2070438/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
