Subject: Re: Dell laptop & apm
To: Phil Nelson <>
From: Jared D. McNeill <>
List: port-i386
Date: 03/11/2005 02:39:01
Phil Nelson wrote:

>  I've just recently acquired a Dell Latitude D600 on which I'm running 
>NetBSD.  I first started with 2.0, but I've moved to -current recently.  In 
>both 2.0 and -current, it doesn't configure an apm(4) interface.  I'm quite 
>sure windows manages to do power management.    I've wandered the BIOS 
>settings to see if there is something there I need to flip.
>   Has anyone else used the D600 and been able to run the apmd an get zzz and 
>apm to work?
As another post mentioned, the D600 BIOS does not support APM. I've 
managed to get ACPI suspend somewhat working in -current on my D600.

To enable sleep, you'll need the following patch to -current:

sysctl -w hw.acpi.sleepstate=1 is fairly stable (although be sure to 
re-run ntpdate after you resume as the system clock stops while asleep). 
The problem with the D600 is that the BIOS sometimes[1] fails to 
re-initialize the Radeon M9 on resume from ACPI S3; I wrote some code 
that uses vm86 mode to send an int10, but it appears that the VM86 
subsystem gets hosed after resume on NetBSD, and it dies with a memory 

Anyway, depending on your specific model (I have a 1.4GHz Pentium-M, and 
resume from S3 doesn't even work well in Windows XP for me), but some of 
the other folks at work haven't had any problems. If you want to test 
S3, simply set hw.acpi.sleepstate=3 and cross your fingers. You'll need 
to press the power button to resume it from S3 sleep.

1: I can successfully suspend/resume from S3 on NetBSD -current so long 
as I go to sleep while docked. If I initiate sleep while undocked, the 
display doesn't get re-initialized (but the machine still responds to 
ssh, ping, etc).