T61p Backlight

I've been having a problem with the back light on my T61p (T7500), after a text terminal (runlevel 3) screen blank (stand by, not suspend?), running Fedora 11. After logging off, the text terminal screen goes blank as a power saving feature. However, upon restore the backlight setting is one fifth full luminosity.

After a bit of digging, the acpitool manual claims it can update the brightness setting (with -l x) using the /proc/acpi/ibm/brightness file. However, the file doesn't exist. I did find the brightness file under /proc/acpi/video/VID1/LCD0/. A redirect of the highest setting restores luminosity (the setting is 1 through 100; after the screen blank it had gone down to 28): echo 100 > /proc/acpi/video/VID1/LCD0/brightness

The last problem is one of persistence. The pm-utils package may provide the answer. After reading documentation in /usr/share/doc/pm-utils/, I was able to construct a script to place in /etc/pm/sleep.d/ which would be run after a resume/thaw:

#!/bin/sh
# 70bl
# pm-utils sleep.d hook to restore backlight.
#
# Copyright 2009 David Egan Evans 
# PO Box 573602, Murray UT 84157 USA
#
# Permission to use, copy, modify, and distribute this software for
# any purpose with or without fee is hereby granted, provided that the
# above copyright notice and this permission notice appear in all
# copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
# WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
# AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
# DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
# OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
# TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

VERSION="0.04"

if [ $# -ne 0 ]; then
 while [ $# -gt 0 ]; do
  case "$1" in
   hibernate|suspend)
        service haldaemon stop
        exit 0
        ;;
   resume|thaw)
        service haldaemon start
        echo 100 > /proc/acpi/video/VID1/LCD0/brightness
        exit 0
        ;;
  esac
 done
fi