Laptop Screen Brightness is Fixed to 100% on kernel 5.9

Same here.

Plus, on my Thinkpad T450, with 5.9.11 Kernel my display won’t shut down for inactivity

I also cannot currently adjust brightness on Lenovo Yoga 2 13, and editing grub settings also didn’t work.

System:    Kernel: 5.9.11-3-MANJARO x86_64 bits: 64 compiler: gcc v: 10.2.0 Desktop: Xfce 4.14.3 tk: Gtk 3.24.23 
           wm: xfwm4 dm: LightDM Distro: Manjaro Linux

Graphics:  Device-1: Intel Haswell-ULT Integrated Graphics vendor: Lenovo driver: i915 v: kernel bus ID: 00:02.0 
           chip ID: 8086:0a16

Did you run sudo update-grub after you edited etc/default/grub?

I got an error:

/etc/default/grub: line 52: i915.enable_dpcd_backlight=0: command not found

Line 52? Show how you have the grub file here

I also have the same issue and problems as Benny.

Figured it out by putting the parameter on line 6 in /etc/default/grub and then updating grub with the command sudo update-grub, and then reboot. Thanks.


Worked for me, thank you!

Made an account to say that this worked for me too on a Dell 7250 with Intel graphics. Thanks!

will this work on my laptop which has Dual graphics. (Asus Zenbook pro duo)
Intel + Nvidia ?

It will probably. Mine has intel + nvidia too and it works for me. You can try it without permanently changing anything. In GRUB menu press e key and add that parameter at the end of the related line. If it breaks something don’t worry after you reboot, everything will turn back to default. If it works great. Just add it to your /etc/default/grub and do sudo update-grub and it will be permanent.

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thanks. I added at the end of this line below. i915.enable_dpcd_backlight=0
But it didn’t have any effect ! Please suggest

Yes you have added it to right place. Looks like something different is going on in your case. Can you adjust your brightness on LTS kernel?

Sorry Im a newbie here. not sure what you meant

That’s OK. Open Manjaro Settings Manager and click on the creepy penguin icon that says Kernel. Then check which kernels are installed on your system. If the latest LTS kernel (which means Long Term Support) which should be 5.4.* is not installed, install it. Reboot and at the grub menu select second entry about manjaro (which is a submenu that lets you select other kernels to boot with), select LTS kernel you’ve installed and after it boots check if your screen brightness is working as expected. If it works and you want to stick with the LTS kernel you can remove 5.9 kernel same way you install LTS kernel or you can define LTS kernel as default in the grub configuration. I don’t remember the full process for it but I’m sure you can find it online with a quick search. If LTS kernel doesn’t solve your problem then it’s probably something different and I suggest you to open another thread for your issue

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Hi, thanks for helping.

I tried quiet apparmor=1 security=apparmor resume=UUID=6f1352f1-5ab6-41a5-8c20-1b3267bf0ae6 udev.log_priority=3 i915.enable_dpcd_backlight=0 with 5.4 and as well with 5.8

still no effect. But I gone ahead I added this to 5.8’s grub file it didnt break anything but no effect.

GRUB_CMDLINE_LINUX_DEFAULT="quiet apparmor=1 security=apparmor resume=UUID=6f1352f1-5ab6-41a5-8c20-1b3267bf0ae6 udev.log_priority=3 i915.enable_dpcd_backlight=0"

[UPDATE] Kernel 5.10 fixed this issue for me. I don’t need to set i915.enable_dpcd_backlight=0 anymore. Brightness control works as expected.

It is needed, because of the OLED patch added

Tried this for my Lenovo T460s and this works like a charm!

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