After upgrading my Toshiba Z830 Ultrabook to 12.04 (Precise Pangolin) I noticed that the ability to control the screen back-light was not working using the Toshiba Fn F6/F7 keys.

Thanks to the solution was found quite quickly.

sudo vim /etc/default/grub

This will open the grub configuration file. (Grub is the initial boot selection software)
To be able to dim the screen brightness, You’ve got to modify the line:


to these two lines:

GRUB_CMDLINE_LINUX="quiet splash pcie_aspm=force i915.i915_enable_rc6=1 i915.lvds_downclock=1 acpi_osi=Linux acpi_backlight=vendor elevator=noop"

Another neat tip: intel-gpu-tools can be used to control brightness from the commandline.

# will set brightness at 50%
intel_backlight 50

EDIT [2012-08-24]: to avoid issues on resume you need to add a script to the

sudo vim /etc/pm/sleep.d/20_wakeup

Add the following:

case "$1" in
#do nothing
echo 7 > /sys/class/backlight/toshiba/brightness
exit 1
exit 0

Mark the file as executable
sudo chmod +x /etc/pm/sleep.d/20_wakeup

Leo Gaggl

ict business owner specialising in mobile learning systems. interests: sustainability, internet of things, ict for development, open innovation, agriculture

This Post Has 8 Comments

  1. Richard Ames

    My install worked without the modification to the grub boot.

  2. Jens

    Hello. You seems familiar with Ubuntu 12.04 and Toshiba.
    I have Toshiba Sattelite something. (Not at the machine at the moment)
    I have suspicion all FN functions are off. Worked in 11.10.
    Somehow the FN functions are all off. WI-Fi, bluetooth, touchpad.
    Wanted to try to fix the FN problem, before trying to fix individual components, as they might be OK, if I could activate them with FN key’s.

    Do you have solution for this.?

    Best regards.

  3. Daniel

    thanx for your article. we just installed ubuntu 12.04 (32bit i guess) and it works fine, no problems. well except… mobile broadband is painfully slow, fluctuating between 10-100kB/s when downloadig with firefox. thing is, it definitely worked much faster with windows7, in the same location. any ideas?

  4. Daniel

    forgot to mention, it’s some hawei dongle, running through gnome network manager, we didn’t install anything, just default settings.

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