[Dell Inspiron 7573] Screen brightness changing randomly with kernel 5.11.0-25

[Felipe Butcher]

Hello guys!

The brightness of the screen on my laptop (Dell 7573 with touch ips 1080 panel) slightly changes randomly when using the laptop builtin display. It feels the same as I changed the brightness one step using the keyboard keys.

Here is a video: https://drive.google.com/file/d/1XQLXKLWu2TlOoGP-p8eaUGZR78713ErH/view?usp=sharing

I suffer with this problem since a long time ago. I think since ubuntu 19. I tried everything you can imagine, I will make a list of things I've tried. I had gave up trying to fix this already but in a beautiful sunny day suddenly the bug stopped happening. So I decided to report this bug now because this bug does NOT happen with only this version of the kernel: Linux 5.11.0-16-generic. So that can probably e useful to help discovering the bug reason.

I am choosing this version on grub every time I reboot so the bug doesn't happen. If I boot on 5.11.0-25 the bug is back.

List of things I've tried:
- Changing i915 parameters like enable_psr to false and many others.
- Upgrading BIOS version.
- Installing windows and applying all the patches on dell's website and installing ubuntu again.
- Disabling "dynamic backlight control" on BIOS.

Some maybe useful info:
- I've tried other distros like Fedora and PopOS and the same bug happens.
- The bug does not happen when using live ubuntu from usb.
- When you fresh install ubuntu (I've tried with 20.04, 20.10 and 21.04) the bug doesn't happen when you have just installed the os but it starts again after the first update. The same applies to the other distro's mentioned above.
- When you disable i915 driver with modeset parameter, it does not happen.
- The bug does NOT happen only with this kernel version 5.11.0-16-generic, BUT it starts happening again if I lock screen and login again. So I am never locking my screen and holding this kernel version for now.

Thanks guys!

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: xorg 1:7.7+22ubuntu1
ProcVersionSignature: Ubuntu 5.11.0-16.17-generic 5.11.12
Uname: Linux 5.11.0-16-generic x86_64
ApportVersion: 2.20.11-0ubuntu65.1
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: pass
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Thu Jul 29 20:54:14 2021
DistUpgraded: Fresh install
DistroCodename: hirsute
DistroVariant: ubuntu
DkmsStatus:
 virtualbox, 6.1.18, 5.11.0-16-generic, x86_64: installed
 virtualbox, 6.1.18, 5.11.0-25-generic, x86_64: installed
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation UHD Graphics 620 [8086:5917] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Dell UHD Graphics 620 [1028:07ec]
InstallationDate: Installed on 2021-07-25 (4 days ago)
InstallationMedia: Ubuntu 21.04 "Hirsute Hippo" - Release amd64 (20210420)
MachineType: Dell Inc. Inspiron 7573
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.11.0-16-generic root=UUID=663d1a67-7acb-428f-a6c8-a9a259a5427c ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/06/2021
dmi.bios.release: 1.18
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.18.1
dmi.board.name: 023FRC
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 31
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.18.1:bd05/06/2021:br1.18:svnDellInc.:pnInspiron7573:pvr:rvnDellInc.:rn023FRC:rvrA00:cvnDellInc.:ct31:cvr:
dmi.product.family: Inspiron
dmi.product.name: Inspiron 7573
dmi.product.sku: 07EC
dmi.sys.vendor: Dell Inc.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.105-3~21.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 21.0.1-2
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.11-1ubuntu1.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200714-1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-1

[Daniel van Vugt (vanvugt)]

I know this issue is annoying but it's also a feature and not a bug. To turn it off (after you have logged in) go to:

  Settings > Power > Power Saving > Automatic Brightness = OFF

[Felipe Butcher (felipebutcher)]

Hey thanks. If it's feature why it doesn't happen on this particular kernel version?

Also my power settings does not show this option. I already tried changing it with dconf-editor.

I still think it's a bug.

[Daniel van Vugt (vanvugt)]

The feature will not appear in the GUI if you're running a kernel version that doesn't support it (or on ~50% of laptops that also don't support it). You can force the setting off unconditionally with:

  gsettings set org.gnome.settings-daemon.plugins.power ambient-enabled false

But the setting is different for each user, so the above command will only stop it happening on the desktop but won't stop it happening on the login screen (user 'gdm').

[Felipe Butcher (felipebutcher)]

The above command didn't make any difference. My computer doesn't even have a light sensor.

I have tried this before but I just tried again to make sure. I will have to keep holding the kernel version for now.

Thanks.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Felipe Butcher (felipebutcher)]

Since the -16 version of the kernel was not available anymore, the bug was back for me. I then downloaded and installed 5.11.1-051101-generic with mainline and the bug is NOT happening with this kernel version. Hope this info helps. Thanks.

[P B (hairmonster90)]

Hi there. I'm having the same problem. When I'm looking at Firefox the screen is nice and bright. When I click on XTerm right next to it, the whole screen dims noticeable. I can do a video of it and replicate on demand if needed. When I click back on Firefox, the whole screen brightens back up. This is a fresh install of 22.04 - jammy. Ubuntu 22.04.1 LTS

I'm running a normal desktop (not laptop) with a Nvidia 3070ti video card. So there is no video sensor to tell if the room is bright or dark. I've tried "xrandr --output HDMI-0 --brightness 1" but that didn't make any difference.

AMD® Ryzen 5 3600 6-core processor × 12

# cat /etc/debian_version
bookworm/sid

Linux myHost 5.15.0-53-generic #59-Ubuntu SMP Mon Oct 17 18:53:30 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

GNOME Version 42.5

[P B (hairmonster90)]

I put in a Nvidia 3080 card with the 470 driver and the problem has gone away if that helps anyone. So possibly a driver issue for me on the video card.