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

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