Ubuntu 20.04 brightness problem

I have upgraded my system to Ubuntu 20.04 and am facing brightness issues. The brightness slider is also not showing up. Tried fixes such as brightness controller, made changes to gedit admin:///etc/default/grub (changed acpi backlight to vendor - no fix, changed to video - no fix). Also created file in /use/share/X11/xorg.conf.d/20-intel.conf and changed it. No fix. Please provide any solution.

Hi Anshuman_Ranjan,

Welcome to our forums.

Have you tried the brightness settings buttons on your keyboard (assuming you have them)? Those aren’t working as well?

Yes I have done them. No effect at all.

Strange. Did you tried to update your 20.04 installation since upgrade? The major release is still relatively new.

Yes I did. Did everything as specified in any good installation tutorial. By the way now I have fresh installed Ubuntu and everything is good now. But I wonder why it was happening just to fulfill my curiosity.

A good question. X11 logs may provide some hints on what went wrong, if you still have them.

X11 logs are for Xorg X11 server stored in the file /var/log/Xorg . Google Search says this log is helpful for diagnosing issues with your X11 environment. But I knew my graphics driver was nvidia geforce 940mx version 440(latest one). I also tried to change the graphics driver to Intel. Nothing happened.

I feel there’s some compatibility issue which may have arised due to Nvidia and it stayed as a permanent edit in any of ubuntu’s graphics file.

There is a full length video of Linus Torvalds where at one point he shows his resentment towards Nvidia support. Since new users can’t post links on this forum so can’t I. But you can check it out by searching Aalto Talk with Linus Torvalds [Full-length] on Youtube.