power

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 http://www.linlap.com/wiki/acer+aspire+s3 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: GRUB_CMDLINE_LINUX="" to these two lines: pcie_aspm=force 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: #!/bin/bash case "$1" in suspend|hibernate) #do nothing ;; resume|thaw) echo 7 > /sys/class/backlight/toshiba/brightness ;; *) exit 1 ;; esac exit 0 Mark the file as executable sudo chmod +x /etc/pm/sleep.d/20_wakeup