# Brightness not working Ubuntu 20.04 Lenovo Legion 5 (15IMH05)

**URL:** <https://forums.developer.nvidia.com/t/brightness-not-working-ubuntu-20-04-lenovo-legion-5-15imh05/178058>\
**Category:** Linux\
**Tags:** ubuntu\
**Created:** [May 15, 2021, 9:08pm UTC](https://forums.developer.nvidia.com/t/brightness-not-working-ubuntu-20-04-lenovo-legion-5-15imh05/178058 "2021-05-15T21:08:32Z")\
**Posts on this page:** 1\
**Showing post:** 22

<div class="post-metadata">

**Author:** ![dios](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@dios](https://forums.developer.nvidia.com/u/dios)\
**Post date:** [November 21, 2021, 10:53am UTC](https://forums.developer.nvidia.com/t/brightness-not-working-ubuntu-20-04-lenovo-legion-5-15imh05/178058/22 "2021-11-21T10:53:35Z")

</div>

nvidia.NVreg\_RegistryDwords=EnableBrightnessControl=1 works for me!

> [@Brightness not working Ubuntu 20.04 Lenovo Legion 5 (15IMH05)](https://forums.developer.nvidia.com/t/brightness-not-working-ubuntu-20-04-lenovo-legion-5-15imh05/178058/17):
>
> FINALLY!!! IT WORKS!!! What works for me is this flag in /etc/default/grub: nvidia.NVreg\_RegistryDwords=EnableBrightnessControl=1 This is my grub file content: GRUB\_DEFAULT=0 GRUB\_TIMEOUT\_STYLE=hidden GRUB\_TIMEOUT=0 GRUB\_DISTRIBUTOR=`lsb_release -i -s 2\> /dev/null || echo Debian` GRUB\_CMDLINE\_LINUX\_DEFAULT="quiet splash nvidia.NVreg\_RegistryDwords=EnableBrightnessControl=1" GRUB\_CMDLINE\_LINUX="" Then of course run: sudo update-grub Source: [https://bugs.launchpad.net/ubuntu/+source/nvidia-g…](https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-455/+bug/1905591)

The `/etc/default/grub` file.

```auto
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nvidia.NVreg_RegistryDwords=EnableBrightnessControl=1"

```

```bash
sudo update-grub

```

But I have set ‘ **Discrete graphic** ’ in BIOS Settings. I haven’t other changes of a clear system, only grub and BIOS.

 ![2021-11-21 13-37-21](https://global.discourse-cdn.com/nvidia/original/3X/d/8/d8c79d7efbfd8abf9c8c3874ca4ef15afdcb447e.jpeg)

Without this configuration it didn’t work for me. Also I had limited settings for NVIDIA settings when I had Security Boot Enable. When I had `Security Boot - Disabled` I had more settings, but I hadn’t display configuration.

When I have updated BIOS settings and Grub I have got worked brightness.

My laptop is Lenovo Legion 5 Gen 6 (NVIDIA + Intel graphics):

- NVIDIA Corporation GA107BM [GeForce RTX 3050 Ti Mobile]
- 11th Gen Intel(R) Core™ i7-11800H  
NVIDIA driver 470.82.00 from Ubuntu Additional drivers.

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