Score:4

Ubuntu

Screen Brightness Issues on Lenovo Legion 5 pro 2021 (ubuntu 20.04)

Van Wilder

2/8/23, 6:00 AM

I have a Lenovo Legion 5 pro (2021), I tried installing ubuntu 20.04.

The problem is that I can't seem to change the brightness at all, it is at max.

Laptop Spec

**Processor** 
    AMD Ryzen™ 7 5800H Processor (8 Cores / 16 Threads, 3.20 GHz, up to 4.40 GHz with Max Boost, 4 MB Cache L2 / 16 MB Cache L3)

**Display Type**
    40.64cms (16.0) WQXGA (2560x1600) IPS 500nits Anti-glare 165Hz 100% sRGB Dolby Vision HDR 400 Free-Sync G-Sync DC Dimmer

***Memory*** 
    16 GB SO-DIMM DDR4 3200MHz

**Graphics** 
    NVIDIA® GeForce RTX™ 3060 6GB GDDR6

**Wireless**
    Wi-Fi 6, 802.11ax 2x2 Wi-Fi + Bluetooth® 5.1, M.2 Card

Just scroll down and you will see the details of the laptop, mine is with RTX 3060.

Any kind of help is appreciated, I have also heard that upgrading to ubuntu 21.04 helps?

Edit There is a hack that works xrandr --output DP-4 --brightness 0.5 but again this is a temporary solution and the controller still does not work.

I also tried to change xorg.conf file, i simply added.

Option "RegistryDwords" "EnableBrightnessControl=1"

It did not work. :,)

Edit More weirdness, now the xrandr hack gets disabled automatically and I have to run it again and again.

On top of the if the session gets suspended, the screen does not come back, like it stays blank and sometimes it comes back but it is very very dim. Not sure what's happening there.

Edit (5/12/21) I have started to use the AMD GPU to save power while using the laptop but the issue is not fixed.

2197

0 + 0

xubuntu

lenovo

20.04

David

2/8/23, 6:27 AM

No pictures of text please cut and paste into the body of the question.

David

2/8/23, 6:30 AM

Does this answer your question? [Lenovo Legion 5 15IMH05H brightness control problem](https://askubuntu.com/questions/1293159/lenovo-legion-5-15imh05h-brightness-control-problem)

David

2/8/23, 6:30 AM

Dupe question. https://askubuntu.com/questions/1293159/lenovo-legion-5-15imh05h-brightness-control-problem

Van Wilder

2/8/23, 6:36 AM

This problem is on multiple variants, hence why I asked it in a different question. The whole `xrandr` thing works but it is a temporary solution to a much larger issue at hand. Why is it not working with the controller?

Van Wilder

2/8/23, 6:53 AM

Besides the xrandr, nothing on that post works, but thank you for the response.

Score:5

Ubuntu

Pierre

4/1/23, 2:51 PM

If your BIOS is set to dynamic / hybrid mode

Edit grub’s config:

sudo vim /etc/default/grub

Change the line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

To:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_native_backlight=1"

Then run:

sudo update-grub

And restart the laptop.
(source: VV0JC13CH)

NB if you’re experiencing screen flickering try downgrading nvidia’s driver from v495 to v470

If your BIOS is set to discrete mode (with nvidia driver)

Edit grub’s config:

sudo vim /etc/default/grub

Change the line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

To:

GRUB_CMDLINE_LINUX="nvidia-drm.modeset=1 acpi_backlight=native nvidia.NVreg_RegistryDwords=EnableBrightnessControl=1"

Then run:

sudo update-grub

And restart the laptop.
(source: BertRAMAerts here)

0 + 0

Van Wilder

4/5/23, 9:22 AM

It did not work, see the problem is that GPU is dynamic and switches between the NVidia and AMD one I think? Not 100% sure. But for now, the AMD one is active.

Pierre

4/7/23, 12:23 AM

@VanWilder Have you tried GRUB_CMDLINE_LINUX_DEFAULT=“quiet splash amdgpu.backlight=0”

Van Wilder

4/7/23, 6:38 AM

`GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"` I was using this so I assumed that it will handle it?

Van Wilder

4/7/23, 6:46 AM

I also tried putting `amdgpu.backlight=0` but it didn't work-

Pierre

4/9/23, 6:24 PM

@VanWilder . I found a solution that works when in hybrid mode. check my updated answer!

Van Wilder

4/10/23, 7:35 AM

This is officially working!! Thank you!

Van Wilder

4/10/23, 7:38 AM

you should check out the other issues I am facing on the same laptop. It is a storm of problems in running Linux on this laptop.

dan carter

4/20/23, 10:23 PM

This worked for me, i have the bios set to discrete mode as i use an external display. Damn i wish Lenovo would let you order this laptop without discrete NVIDIA graphics. Amd graphics would be so much more stable.

Van Wilder

5/13/23, 5:22 AM

@Pierre For some reason my monitor was not working with this, so I installed 22.04 which practically solved all the issues but gave rise to another issue. https://askubuntu.com/questions/1408276/monitor-scaling-issue-on-ubuntu22-04.

Score:0

Ubuntu

d3cbl

4/26/23, 9:08 AM

I had the same issue on my L5P 16ACH6H even after editing both grub and xorg.conf like the other answers here mentioned.

What finally solved it for me was to install an OEM kernel. I believe either 20.04c (5.13) or 20.04d (5.14) is required since the Mediatek wireless card drivers requires at least 5.12 to work. In my case I installed 20.04d using

sudo apt install linux-oem-20.04d

and now brightness control works together with WiFi+BT.

0 + 0

Arnas Ivanavičius

4/5/23, 8:31 PM

Finally, something works!

Van Wilder

4/27/23, 10:26 AM

Will it give me unsigned errors or something similar, when I was trying to install the HWE version kernel, it was creating issues.

d3cbl

4/27/23, 4:45 PM

I'm not sure about that sorry. If it helps I'm using the discrete GPU mode with nvidia-driver-495 and I didn't encounter any errors. The WiFi is a bit iffy sometimes (I can't detect 5GHz connections sometimes but turning WiFi off and on fixes it) but I think that's just due to the subpar Mediatek card.

Van Wilder

4/29/23, 2:02 PM

It is working though, I will be testing it out as much as I can.

Van Wilder

5/14/23, 2:16 PM

It only works with dynamic graphic mode through. :)

Score:0

Ubuntu

elmclose

2/8/23, 9:26 AM

Sometimes the ACPI is implemented improperly on the motherboard. One solution is to add the parameters acpi_osi=linux and acpi_backlight=video to your kernel command lines in Grub.

Open the file /etc/default/grub using gedit or any other text editor. Look for this line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

and change it to

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

This would load device specific drivers before default drivers in Linux.

Save and close text editor.

Now update your grub:

sudo update-grub

And reboot and see what happens.

0 + 0

Someone

2/8/23, 9:51 AM

Didn't worked when I tested on ubuntu 20.04 virtual machine

Van Wilder

2/8/23, 10:40 AM

This does not work.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Screen Brightness Issues on Lenovo Legion 5 pro 2021 (ubuntu 20.04)

TH: ปัญหาความสว่างของหน้าจอใน Lenovo Legion 5 pro 2021 (ubuntu 20.04)

RO: Probleme de luminozitate a ecranului pe Lenovo Legion 5 pro 2021 (ubuntu 20.04)

RU: Проблемы с яркостью экрана на Lenovo Legion 5 pro 2021 (ubuntu 20.04)

VI: Sự cố về độ sáng màn hình trên Lenovo Legion 5 pro 2021 (ubuntu 20.04)

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.