Change /etc/default/grub

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3

13.10 Can't Adjust Dell Laptop Backlight

rated 0 times [ 3] [ 0] / answers: 1 / hits: 7980 / 3 Years ago, wed, august 4, 2021, 2:26:58

I have a Dell Studio 1558. When I originally installed 13.04 on it, I had to modify my /etc/default/grub with the following:

GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=vendor dell_laptop.backlight=0 quiet splash"

Doing that made everything work, the keyboard brightness buttons, the OSD in the top right corner, and the brightness slider in System Settings. However, upon upgrading to 13.10, I once again am unable to adjust the backlight. This is also the case if I use either of the following:

GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=vendor quiet splash"  

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

The backlight is stuck at a single brightness level, at a guess I think it's somewhere around 50%. The OSD still comes up if I push the keyboard buttons, but the bar only goes down one division from 100% and resets back to 100%, if I press decrease again. The slider in 'System Settings' does nothing.

Any help is greatly appreciated!

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oargrou

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answered 3 Years ago polcomposte · Accepted Answer

Doing both of the steps mentioned here fixed this issue with a Dell Studio 1558 and Ubuntu 13.10: http://ubuntuforums.org/showthread.php?t=2181534

Change /etc/default/grub

I used "sudo vim /etc/default/grub" but use whatever editor you're comfortable with but you will need to use sudo to edit it as the root user.

From:

GRUB_CMDLINE_LINUX="acpi_backlight=vendor"

To:

GRUB_CMDLINE_LINUX=""

Then run:

sudo update-grub

Add /usr/share/X11/xorg.conf.d/20-intel.conf

I used "sudo vim /usr/share/X11/xorg.conf.d/20-intel.conf" and then ran :set paste and hit i for insert and pasted in the contents.

Section "Device"

    Identifier  "card0"

    Driver      "intel"

    Option      "Backlight"  "intel_backlight"

    BusID       "PCI:0:2:0"

EndSection

Then reboot and login again and your function key with the brightness up/down should work again.