Backlight does not turn off during screen blanking

[Michał Fita]

In the 2022/2023 energy crisis era, this shall not happen. But... I haven't found solution other than "switch to X", which is not an options with my scaling settings for both 4K screens I'm using.

On idle when the system blanks screen backlight remains on, wasting energy and burning LEDs in my screens. Please provide solution that would let Gnome set DPMS properly and actually send screens to proper sleep when OS goes idle (enables screen saver).

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: libwayland-bin 1.20.0-1ubuntu0.1
ProcVersionSignature: Ubuntu 5.15.0-58.64-generic 5.15.74
Uname: Linux 5.15.0-58-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu82.3
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: pass
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Tue Feb 14 11:59:59 2023
DistUpgraded: Fresh install
DistroCodename: jammy
DistroVariant: ubuntu
DkmsStatus:
 v4l2loopback/0.12.5, 5.15.0-58-generic, x86_64: installed
 v4l2loopback/0.12.5, 5.15.0-60-generic, x86_64: installed
GraphicsCard: Advanced Micro Devices, Inc. [AMD/ATI] Rembrandt [1002:1681] (rev d1) (prog-if 00 [VGA controller])
InstallationDate: Installed on 2023-01-04 (40 days ago)
InstallationMedia: Ubuntu 22.04.1 LTS "Jammy Jellyfish" - Release amd64 (20220809.1)
MachineType: LENOVO 21CKCTO1WW
ProcKernelCmdLine: BOOT_IMAGE=/BOOT/ubuntu_zrhf1w@/vmlinuz-5.15.0-58-generic root=ZFS=rpool/ROOT/ubuntu_zrhf1w ro quiet splash
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: wayland
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/11/2022
dmi.bios.release: 1.32
dmi.bios.vendor: LENOVO
dmi.bios.version: R23ET62W (1.32 )
dmi.board.asset.tag: Not Available
dmi.board.name: 21CKCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: ThinkPad
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.23
dmi.modalias: dmi:bvnLENOVO:bvrR23ET62W(1.32):bd11/11/2022:br1.32:efr1.23:svnLENOVO:pn21CKCTO1WW:pvrThinkPadP16sGen1:rvnLENOVO:rn21CKCTO1WW:rvrThinkPad:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_21CK_BU_Think_FM_ThinkPadP16sGen1:
dmi.product.family: ThinkPad P16s Gen 1
dmi.product.name: 21CKCTO1WW
dmi.product.sku: LENOVO_MT_21CK_BU_Think_FM_ThinkPad P16s Gen 1
dmi.product.version: ThinkPad P16s Gen 1
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.113-2~ubuntu0.22.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 22.2.5-0ubuntu0.1~22.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:21.1.3-2ubuntu2.7
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-2ubuntu1
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

[Daniel van Vugt (vanvugt)]

While this sounds close to bug 2003237, I now realise that might be a different issue.

[Daniel van Vugt (vanvugt)]

Try adding this to /etc/environment:

  MUTTER_DEBUG_ENABLE_ATOMIC_KMS=0

and then reboot.

[Daniel van Vugt (vanvugt)]

Please also try to capture the part of the system log (using journalctl) showing when the problem occured.

[Daniel van Vugt (vanvugt)]

OK, confirmed to be the same as bug 2003237.

[Michał Fita (michal.fita)]

The wake-up from sleep is around 11:26. There's a lot of stuff before, so maybe you can find something.

I've added the flag to the environment, but from what I see the backlight remains on (it's sunny day, so hard to spot, but shading screen seem to show lights in corners).

Hope that helps.

[Daniel van Vugt (vanvugt)]

/home/manveru/.local/share/gnome-shell/extensions/multi-monitors-add-on@spin83 is logging a lot of errors so is likely to cause bugs. Please remove unsupported extensions:

  cd ~/.local/share/gnome-shell
  rm -rf extensions

and then log in again to confirm if the bug still occurs.

Your log also shows that prior to using MUTTER_DEBUG_ENABLE_ATOMIC_KMS=0 you were experiencing bug 1968040. So at least that should be fixed now.