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[My name <plmalternate@xxxxxxxxx>]

Still doesn't work in Saucy.  
For me, none of the following, cause any change in screen appearance, nor to they bring any response in lxterminal other than a new prompt:

xbacklight -get
xbacklight -set 100 -time 0
xbacklight -set 20 -time 0
xbacklight -set 2 -time 0

Running Saucy in plain openbox, no lxde other than lxterminal.

Also, as an aside, I think #4 may be misleading in saying "The xrandr program also works fine."
These commands work fine:
[code]
# Sets the "brightness" (i.e., thev transparency) of the LCD layer very dark:
xrandr --output VGA-0 --brightness 0.1
# Legitimate values are 0 to 1
# Sets the "brightness" (i.e., thev transparency) of the LCD layer all the way up:
xrandr --output VGA-0 --brightness 1
[/code]
but, unless I've misunderstood man xrandr they DO NOT affect the actual brightness of the backlight. In a well lit room, the effect looks very similar, but in a dark room the difference should be apparent.

It may be I haven't figured out the syntax correctly, but for me in Saucy, none of these do anything:
[code]
xrandr --output VGA-0 --set backlight 50
xrandr --output LVDS-0 --set backlight 50
xrandr --output --auto --set backlight 50
xrandr --output auto --set backlight 50
[/code]

-- 
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https://bugs.launchpad.net/bugs/1054298

Title:
  xbacklight doesn't work, but xrandr does and so does
  /sys/class/backlight

Status in “linux” package in Ubuntu:
  Expired

Bug description:
  Sony Vaio P
  Ubuntu Precise and Quantal
  kernel 3.5.0
  gma500_gfx kernel driver
  modesetting xorg driver
  Assume the current quantal & quantal-proposed versions of everything.

  xbacklight doesn't work. No backlight change, and no output from the program.
  "xbacklight" and "xbacklight -get" show nothing, no output from the program at all.
  "xbacklight -set50" and "xbacklight-d :0 -set 50" does nothing nor prints any output.

  However both sysfs and xrandr work fine.

  Specifically:
  xrandr --verbose lists outputs and shows the main screen has backlight property,
  and "xrandr --output LVDS-0 --set backlight 50" changes the backlight brightness.

  And

  "cat /sys/class/backlight/psb-bl/actual_brightness" shows the current brightness, and
  "echo 50 >/sys/class/backlight/psb-bl/brightness" changes the brightness.

  I have written the following script to use in place of xbacklight:
  http://forums.bodhilinux.com/index.php?/topic/5985-brightness-scripts/page__view__findpost__p__56911

  This script, both the sysfs and xrandr methods of it, works fine for me on the same machine.
  (for sysfs, I had to make a udev rule to allow users to write to the sysfs files, as noted on that page and in the --help output of the script)
  It requires zenity for the user interactive options. Not needed for the non-interactive options.

  -- 
  bkw

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