Ubuntu – Cannot adjust brightness after sleep


I have a Toshiba Satellite R830 laptop with Ubuntu 12.04.1 64 bit. The Fn + F6 and Fn + F7 buttons adjust brightness until I put my laptop on sleep.

On wakeup they don't work any longer. Is there a solution or a workaround to this issue?

Best Answer

I found a better solution than the one selected above.

  1. Press Alt + F2 and type gksudo gedit /etc/default/grub.
  2. Find the line than starts with GRUB_CMDLINE_LINUX_DEFAULT= and modify it as follows: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor".
  3. In a terminal (ctrl + alt + T) type sudo update-grub.
  4. Reboot.

Problem solved.

More info here: https://wiki.ubuntu.com/Kernel/Debugging/Backlight


This solution no longer works on 13.10 and 14.04.

A solution that does is creating an xorg configuration file:

  1. In a terminal type sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf to create the file.
  2. Followed by sudo gedit /usr/share/X11/xorg.conf.d/20-intel.conf to edit its content.
  3. Then add the following content and save:
Section "Device"
        Identifier  "card0"
        Driver      "intel"
        Option      "Backlight"  "intel_backlight"
        BusID       "PCI:0:2:0"


Log out and in again.

Source: Fix Brightness Control Not Working for Ubuntu 13.10 & 14.04

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