Ubuntu – How to adjust the screen brightness on an Acer Aspire One D270


My system specifications are: Ubuntu 12.04, 64-bit, Acer Aspire One D270, Intel Atom CPU

The usual brightness increase/decrease key combination using Fn key doesn't work in Ubuntu as many pointed out.

I had found two solutions on this forum to set the screen brightness.

One was to make the usual key combination work answer is given here:

Is there a way to set a hotkey to change screen brightness?

and the other is using the command

sudo setpci -s "00:02.0" F4.B=20

where the 20 is a hexadecimal number representing brightness.

It's only the latter that worked in my case.

I observe that the original brightness setting is restored after resumption from sleep mode.

All I want is to keep my brightness setting permanent. How do I do that?

Try 1: Tried Alok's suggestion. It just sits there as a startup application. Doesn't figure as an icon on the topbar of the screen, like the dropbox icon (my dropbox account it is linked to ubuntu) so that I can conveniently change the brightness.

Try 2: Also I must add, that the method System Settings -> Additional Drivers gives an empty list. In my earlier install (which I had to overwrite-reinstall :-(), the list had (I think) Intel Cedarview Graphics Driver. So must I install before trying the methods in any of the answers below?

Update: I read somewhere Intel CedarView is only for 32-bit OS!

Try 3: Just tried the quiet_splash etc that I had to add to /etc/default/grub, even read the thread given in one of the answers below!

Temporarily settled myself with this method:

  • Pasted the setpci brightness command in a bash file brightness.sh
  • Created a .desktop file for the command bash brightness.sh
  • Made it an executable file.

    Try 4a: I created an environment variable BRI ensured using env it's there in the list, and tried using it, here's the bash file brightness.sh

    echo "Set Brightness (Values 00-FF): "
    read s
    sudo setpci -s "00:02.0" F4.B=$s
    export BRI=s

    However I have to give the administrative password, and have yet not succeeded in making it a permanent setting and am working on these aspects!

    Try 4b: I even tried (in vain)

  • pasting the export BRI into /etc/default/grub and /etc/grub.conf
  • appending the same to ~/.bashrc and to /etc/bash.bashrc through the shell script brightness.sh that I made

    as I in each case restart and find BRI to still have its old value, and not the one given by executing brightness.sh via the launcher!

  • Best Answer

    Possibly, the second solution posted in this thread applies to your laptop as well: passing the options acpi_osi=Linux acpi_backlight=vendor to grub. Try to edit the line starting with "GRUB_CMDLINE_LINUX" in the file /etc/default/grub to:

    GRUB_CMDLINE_LINUX="quiet splash acpi_osi=Linux acpi_backlight=vendor"

    and then run

    sudo update-grub

    Maybe this will help.