Problem with LCD backlight remaining on during ACPI sleep
Revision as of 14:35, 29 November 2005 by 213.39.155.53 (Talk) (hwclock has nothing to do with this solution)
Problem description
On some models the LCD backlight remains on during ACPI sleep.
Affected Models
(according to the relevant bug on the Kernel bug tracker (bug 2576))
Partial solution
If the ThinkPad has a radeon video chip, then switching off the light with the command
radeontool light off
will work, but only in a text-mode virtual terminal. If X is running, the light apparently comes back on when the kernel switches to text mode prior to sleeping. The solution in that case it to switch to a text mode console first.
logger "Software suspend to ram." FGCONSOLE=`fgconsole` chvt 1 radeontool light off echo -n 3 >/proc/acpi/sleep logger "Woke up from suspend." radeontool light on chvt $FGCONSOLE
Improvements are clearly possible. :-)
A similar script can be found on the acpid configuration HOWTO page.
