Changing backlight brightness on Ubuntu 12.10

发表于 2013-03-13 更新于 2023-10-03 分类于 Linux

When updating my nvidia drivers, The backlight brightness cannot change.

Follow below steps to fix this problem:

1) Type ‘nvidia-xconfig’ to generate ‘xorg.conf’ file at ‘/etc/X11/‘.

2) Modify the ‘xorg.conf’ file.

3) Add ‘Option “RegistryDwords” “EnableBrightnessControl=1” ‘ in ‘device section’.

4) Reboot and check whether the brightness can change.

If you still cannot change the backlight brightness, see the detailed description.

We need to how the linux works.

When we use the short-key to input brightness up/down, the system modify a value in ‘/sys/class/backlight/acpi_video0/brightness’ directory.

The range is 0 ~ 15 in my laptop, which is probably different on your laptop.

If in your ‘/sys/class/backlight/‘ there exists other device type. you need to confirm which one is currently in use.

Modify the grub file to change the selection.

Open ‘/etc/default/grub’, change ‘GRUB_CMDLINE_LINUX=” “ ‘ to ‘GRUB_CMDLINE_LINUX=”acpi_backlight=vendor“ ‘.

Then type ‘update-grub’ to update the current grub files.

Reboot to see which file receives the changing value when the short-key presses down.

The display driver reads this value to set the brightness level which is out control of us.

So we just can do above things to fix the problem.