0

Before you say this is a duplicate, I've already looked at this and this and that did not solve my problem.

I installed Ubuntu 20.04 LTS and ever since the beginning it has maximum brightness by default, which I want down to like 60-80% or so. I tried xbacklight -set 50, and that doesn't do anything. I also found out I have a /sys/class/backlight directory with folder dell_backlight that has max brightness 15 and intel_backlight that has max brightness 120000.

The Fn+ brightness hotkeys (F11/F12) of the laptop seem to work, it changes the brightness value in dell_backlight/brightness, but it doesn't actually change the brightness of the screen.

That is, the keys themselves work in the sense that they do something, but somehow they don't have the desired effect. If I manually alter the value in intel_backlight/brightness, that doesn't change the brightness of the screen either.

I don't really care so much if the brightness keys work, but most importantly I want to set my default so when I start up it's comfortable and not blindingly bright.

EDIT: the laptop is a dell xps 15 7590

Qwert Yuiop
  • 21
  • You are missing a key bit of information: make and model of your machine. Please edit it into the question. Mind also that some machines also have settings in BIOS for this. – Rinzwind Jun 30 '20 at 11:55
  • This post might help: https://askubuntu.com/questions/818167/screen-brightness-stuck-at-maximum –  Jun 30 '20 at 15:04
  • @elmclose I tried the suggested answer, but all it does is replace the `/sys/class/backlight/dell_backlight' with '/sys/class/backlight/acpi_video0'. The Fn+brightness hotkeys now change the value in 'acpi_video0/brightness' without affecting the actual screen brightness. – Qwert Yuiop Jul 01 '20 at 12:44
  • Other people seem to have had similar issues with their Dell laptops. MS Windows users have come up with odd ways of overcoming it. Check out this link: https://www.dell.com/community/XPS/XPS-15-L521X-Unable-to-Adjust-Screen-Brightness/td-p/6095414 –  Jul 01 '20 at 15:27

0 Answers0