[Ubuntu Wiki] Update of "Kernel/Debugging/Backlight" by penalvch

[Ubuntu Wiki]

Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Ubuntu Wiki" for change notification.

The "Kernel/Debugging/Backlight" page has been changed by penalvch:
http://wiki.ubuntu.com/Kernel/Debugging/Backlight?action=diff&rev1=33&rev2=34

Comment:
As per LP#1460088 added acpi_osi= .

     * {{{echo 8 > /sys/class/backlight/intel_backlight/brightness}}}
      * Please comment on if the brightness changes.
   * Reboot with just kernel parameter video.use_bios_initial_backlight=0 and make a comment on if you can now alter the backlight with hotkeys or a brightness applet.
+  * Reboot with just kernel parameter acpi_osi= and make a comment on if you can now alter the backlight with hotkeys or a brightness applet.
   * If using a v3.13.x+ series kernel, reboot with just kernel parameter video.use_native_backlight=1 and make a comment on if you can now alter the backlight with hotkeys or a brightness applet.
   * If your backlight hotkeys are Fn+Left and Fn+Right, add kernel parameter atkbd.softraw=0 to /boot/grub/menu.lst . Then, switch to any console, e.g. Ctrl+Alt+F1, login by root account and execute:<<BR>> {{{showkey -s}}} <<BR>> <<BR>> Then, press Fn+Left and Fn+Right key to check the code that shows up on screen. Post the results to the report. For example: <<BR>> <<BR>> Fn+Left: <<BR>> 0xe0 0x4c 0xe0 0xcc <<BR>> <<BR>> Fn+Right: <<BR>> 0xe0 0x54 0xe0 0xd4