Subject: Re: apm vs acpi
To: Jan Danielsson <jan.m.danielsson@gmail.com>
From: Steven M. Bellovin <smb@cs.columbia.edu>
List: netbsd-users
Date: 01/03/2007 10:16:18
On Wed, 03 Jan 2007 16:08:00 +0100
Jan Danielsson <jan.m.danielsson@gmail.com> wrote:

..
> 
>    Ah, I see. Hmm... I guess what I was asking for was this: My
> stationary system (NetBSD/amd64 3.0) does not have APM support
> compiled in. And when the screen shuts off due to inactivity, the
> screen does not power down as I want it to. It just "blackens" the
> screen, instead of telling it to shut itself off for a while.

Ah.  Assuming that you're running X, the fix is probably simple -- but
it's in X, not the kernel.  Put something like

	xset dpms 180 240 300

in your .xinitrc (or whatever file you use for things to run at
startup).  You may also need to enable the option in your X
configuration file.  On my systems, which use Xorg, I have

	Option	"DPMS"

in /etc/X11/xorg.conf.  (I have the same line in the config file on an
XFree86 system.)
> 
>    I thought BIOS could handle those things, but no matter what I try,
> nothing helps.
> 
>    While searching around, I found that ACPI (which is enabled in
> BIOS, and which support is compiled into my kernel) should be able to
> do what apm does. But why doesn't my new TFT screen power down,
> instead of showing a black/blue "picture". And why doesn't NetBSD
> power down when I shut down with "-h"?
> 
>    So I thought I'd try with "apm" instead and see if that helps
> either of the issues, but "config" says apm doesn't even exist.

It might not for amd64; I don't have any of those, so I've never tried.
> 
>    Well.. I'm completely lost. Any hints? (I want to get the screen to
> shut down properly, and I would like the system to power down on
> "shutdown -h", if possible).
> 
Send a dmesg.


		--Steve Bellovin, http://www.cs.columbia.edu/~smb