Ubuntu – Brightness problem Ubuntu 18.04 LTS

18.04brightness

I have upgraded to ubuntu 18.04 LTS the display brightness controls are not working. It appears that the brightness is in its lowest level and I am not able to change display brightness at all. It was working on 16.04 LTS. My laptop uses Intel Graphics card.

I have tried to solve that by creating the file /usr/share/X11/xorg.conf.d/20-intel.conf with the following content. It worked the first time, but after one reboot it remains back to the previous problem.

Section "Device"
        Identifier  "card0"
        Driver      "intel"
        Option      "Backlight"  "intel_backlight"
        BusID       "PCI:0:2:0"
EndSection

What can I do?

Best Answer

I also had this problem, but on different distributions the solution was different.

Solution provided by Anas Elazhar worked well until I switched to Xubuntu:

Open the file /etc/default/grub using gedit or any other text editor. Find below line.

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Change above line to

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

If it doesn't work for you either try to change acpi_backlight value to video:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=video"

Also create the file /usr/share/X11/xorg.conf.d/80-backlight.conf but content is slightly different from the file that you created:

Section "Device"
    Identifier  "Intel Graphics"
    Driver      "intel"
    Option      "AccelMethod"     "sna"
    Option      "Backlight"       "acpi_video0"
    BusID       "PCI:0:2:0"
EndSection

If combination acpi_backlight=video with this file doesn't work change acpi_backlight back to vendor.

And do not forget to run sudo update-grub command in terminal every time you change /etc/default/grub!

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