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Claudio Diniz
Asked: 2018-05-10 18:44:41 +0800 CST

Brightness problem Ubuntu 18.04 LTS

  • 772

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?

brightness 18.04

9 Answers

  1. 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!

    • 42

  2. 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"

    This would ensure to load device specific drivers before default drivers in Linux.

    Save the file and close text editor.

    Open terminal and run below command to update grub.

      sudo update-grub

    Reboot.

    After reboot, try adjusting brightness using Laptop dedicated control keys. Good Luck.

    • 9

  3. Installing Brightness Controller helped me in fixing up the issue

     sudo add-apt-repository ppa:apandada1/brightness-controller
 sudo apt update
 sudo apt install brightness-controller

    You can access the Brightness Controller after download by searching for it.

    • 4

  4. Based on my current Ubuntu 18.04 installation (from today), I can adjust brightness at the login screen with the function keys (out of the box!). However, I am using i3 with Gnome, and after login, I am no more shown brightness controls in Gnome control centre.

    Above answers didn't unfortunately work for me: Instead, using Ducky's xorg script together with Grub option made my i3 + Gnome session having undesired display behaviour and getting slower.

    Anyway, at least for the case you go for a non-Gnome session (e.g. i3), I can point you to https://github.com/szekelyszilv/ybacklight which (given you have meson and ninja installed) can be built by:

    • downloading, unpacking and changing into ybacklight main directory
    • mkdir build; meson build; cd build; ninja install

    or, (without those tools and if you don't want to install it in the system), by:

    • cd src; gcc ybacklight.c -o ybacklight; cp ybacklight to-your-pref-dir

    and then be attached to function keys via WMs config. E.g. in i3wm, I added:

    bindsym XF86MonBrightnessUp exec ybacklight -inc 10 
bindsym XF86MonBrightnessDown exec ybacklight -dec 10

    to my .config/i3/config.

    Furthermore, setting brightness requires root privileges, e.g., achievable with "sudo ybacklight ..." as well as an entry to /etc/sudoers: see How can I add a new user as sudoer using the command line?

    • 1

  5. I've recently updated to 18.04 and I have found that changing GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub to the following 

    GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=video"

    and adding,

    Option         "RegistryDwords" "EnableBrightnessControl=1"

    to /etc/X11/xorg.conf under 

    Section "Device"

    fixed the control and brightness keys issues running Nvidia 390 driver.

    • 1

  6. I started the nvidia X server settings and in the x server display configuration changed the selection to X Screen0 and it worked.

    The brightness control works now. Also before doing that I've changed the grub to acpibacklight=video0.

    • 0

  7. On Ubuntu 18.04 (with xfce desktop) my brightness problem finally solved.

    I opened 'Onboard Settings' under the 'Settings' menu. If your desktop doesn't have one, you can download it from Software Center.

    On the 'Onboard Preferences' window, click the Layout menu, then choose the 'Full Keyboard' (Desktop keyboard with edit and function keys). Click here to view the Onboard Settings window

    • 0

  8. I managed to get Brightness control working with nvidia drivers on Debian 10.

    Here is my hardware : - ThinkPad P51 - Nvidia Quadro M2200 GPU + Intel GPU

    Here is how I did :

    • Go to Bios and configure display to Discrete graphics (only Nvidia GPU will be used)

    • Remove Nouveau driver if it is setup

      Add nouveau blacklist to /etc/modprobe.d/nvidia-installer-disable-nouveau.conf

      blacklist nouveau options nouveau modeset=0

      then run

      update-initramfs -u

      then reboot

    • Download and install latest Nvidia driver from Nvidia website (https://www.nvidia.com/Download/index.aspx?lang=en) Mine was version 430.50

      Open a tty console without any X Server launched (Ctrl+Alt+F3 at login page)

      Install linux headers if you don't have ( apt-get install linux-headers-`uname -r` )

      Install driver as root ./NVIDIA-Linux-x86_64-430.50.run (erase libs if requested)

    That's it everyting working perfectly finally !!

    • 0

  9. After creating the file /usr/share/X11/xorg.conf.d/80-backlight.conf and rebooting, I experienced blank screen and I couldn't do anything about it. I have a dual boot machine, so I solved my problem by booting into windows, downloading software to access Linux files and then I deleted the /usr/share/X11/xorg.conf.d/80-backlight.conf that was causing the problem.

    The way I solved my problem:

    1. sudo nano /etc/default/grub
    2. search and change this line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi="
    3. sudo update-grub
    4. Reboot
    • 0