How do I enable keyboard backlight in Ubuntu 20.04.02 on Dell G5 Laptop?

Question

I recently bought a Dell G5 laptop which came pre-installed with Windows OS. However, I removed Windows OS and install Ubuntu 20.04.02 LTS on it. Now, I'm unable to get the keyboard backlight to work and I'm unable to find a solution to this problem.

Solution

Generally you can set the keyboard brightness in the Power Settings:

If you do not see this option, then you may be able to set it via the Terminal, so long as the keyboard makes the backlight settings available. Here's how to check:

0. Open Terminal (if it's not already open)
1. Install brightnessctl (if it is not already installed):

   sudo apt update
   sudo apt install brightnessctl
   

2. Check whether the keyboard brightness settings are accessible:

   brightnessctl --device='tpacpi::kbd_backlight' info
   

   If everything is good, you will see something similar to this:

   Device 'tpacpi::kbd_backlight' of class 'leds':
       Current brightness: 0 (0%)
       Max brightness: 2
   

3. Now you can try to change the brightness:

   sudo brightnessctl --device='tpacpi::kbd_backlight' set 1
   

   If this works, then adjust the brightness to any integer value between 0 and the maximum step supported by your keyboard. If this doesn't work, then you will likely see a message similar to:

   Can't modify brightness: Permission denied
   

Note: Some G5 models come with RGB LEDs under the keyboard but, to the best of my knowledge, there is no means to set the display colours without the Windows-based application.

Comments

[OldTinfoil]

FYI - my device was registered as "kbd_backlight". To find all your backlit devices - use "bightnessctl -l" to get a list. Thanks for your help @matigo

[Adeel Raza Azeemi]

My device was Device 'intel_backlight' of class 'backlight': and brightnessctl --device='intel_backlight' info worked for me. But it only changed the brightness of screen and not the keyboard backlight