Difference between revisions of "Problem with LCD backlight remaining on during ACPI sleep"
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Improvements are clearly possible. :-) | Improvements are clearly possible. :-) | ||
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| + | On the X32, at least, the bios will switch off the screen by default on a lid close, and suspending to ram interrupts this, and the screen will turn back on. This can be fixed by simply adding "sleep 5" before "echo -n 3 > /proc/acpi/sleep". The suspend will take longer, but the screen will remain off. | ||
A similar script can be found on the [[How to configure acpid|acpid configuration HOWTO]] page. | A similar script can be found on the [[How to configure acpid|acpid configuration HOWTO]] page. | ||
Revision as of 20:49, 27 December 2005
Problem description
On some models the LCD backlight remains on during ACPI sleep.
Affected Models
- ThinkPad 390X with kernel boot option ACPI=force
- ThinkPad A30
- ThinkPad A31p
- ThinkPad T30
- ThinkPad X31,X32
- ThinkPad R51
(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. :-)
On the X32, at least, the bios will switch off the screen by default on a lid close, and suspending to ram interrupts this, and the screen will turn back on. This can be fixed by simply adding "sleep 5" before "echo -n 3 > /proc/acpi/sleep". The suspend will take longer, but the screen will remain off.
A similar script can be found on the acpid configuration HOWTO page.
