I wonder if this is caused by uncoordinated KMS updates not relating to displaying the primary plane. I imagine some of those will wake the monitor up even though there's no image to display. And even worse; some of them will come from gnome-settings-daemon beyond the control of gnome-shell/mutter (which is fixed in GNOME 43). To mitigate this, please try disabling features that might cause such updates:
* Settings > Colour > turn OFF for all screens * Settings > Screen Display > Night Light = OFF * Software-controlled privacy screens on some models of laptop -- 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/1973467 Title: [Wayland] Backlight stays on with black screen when monitor should be sleeping Status in mutter package in Ubuntu: Confirmed Bug description: In Power -> Power Saving Options -> Screen Blank - the option states that the screen will be turned off after some period, which is what I'd expect from a sleep mode. I have a hybrid system. I have disabled the internal display and I use the external connected via HDMI (and I believe it is connected to the NVIDIA GPU). When the screen goes blank the external monitor is not turned off really. It goes blank but it is still turned on and glows, so no power is saved. ProblemType: Bug DistroRelease: Ubuntu 22.04 Package: xorg 1:7.7+23ubuntu2 ProcVersionSignature: Ubuntu 5.15.0-27.28-generic 5.15.30 Uname: Linux 5.15.0-27-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia .proc.driver.nvidia.capabilities.gpu0: Error: path was not a regular file. .proc.driver.nvidia.capabilities.mig: Error: path was not a regular file. .proc.driver.nvidia.gpus.0000.01.00.0: Error: path was not a regular file. .proc.driver.nvidia.registry: Binary: "" .proc.driver.nvidia.suspend: suspend hibernate resume .proc.driver.nvidia.suspend_depth: default modeset uvm .proc.driver.nvidia.version: NVRM version: NVIDIA UNIX x86_64 Kernel Module 510.60.02 Wed Mar 16 11:24:05 UTC 2022 GCC version: ApportVersion: 2.20.11-0ubuntu82 Architecture: amd64 CasperMD5CheckResult: pass CompositorRunning: None CurrentDesktop: ubuntu:GNOME Date: Sun May 15 19:16:56 2022 DistUpgraded: Fresh install DistroCodename: jammy DistroVariant: ubuntu ExtraDebuggingInterest: Yes, if not too technical GraphicsCard: Intel Corporation HD Graphics 630 [8086:591b] (rev 04) (prog-if 00 [VGA controller]) Subsystem: Dell HD Graphics 630 [1028:0798] NVIDIA Corporation GP107M [GeForce GTX 1050 Ti Mobile] [10de:1c8c] (rev a1) (prog-if 00 [VGA controller]) Subsystem: Dell GP107M [GeForce GTX 1050 Ti Mobile] [1028:0798] InstallationDate: Installed on 2022-05-01 (14 days ago) InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - Release amd64 (20220419) MachineType: Dell Inc. Inspiron 15 7000 Gaming ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.15.0-27-generic root=UUID=19e3ad11-d1ce-49ce-8809-80fc68612eb3 ro quiet splash vt.handoff=7 SourcePackage: xorg Symptom: display UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 08/30/2021 dmi.bios.release: 1.15 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.15.0 dmi.board.name: 065C71 dmi.board.vendor: Dell Inc. dmi.board.version: X02 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.15.0:bd08/30/2021:br1.15:svnDellInc.:pnInspiron157000Gaming:pvr:rvnDellInc.:rn065C71:rvrX02:cvnDellInc.:ct10:cvr:sku0798: dmi.product.family: Inspiron dmi.product.name: Inspiron 15 7000 Gaming dmi.product.sku: 0798 dmi.sys.vendor: Dell Inc. version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.110-1ubuntu1 version.libgl1-mesa-dri: libgl1-mesa-dri 22.0.1-1ubuntu2 version.libgl1-mesa-glx: libgl1-mesa-glx N/A version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A version.xserver-xorg-core: xserver-xorg-core 2:21.1.3-2ubuntu2 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-2build3 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20210115-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-2build1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1973467/+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