Subject: Re: power management and idle detection on non-x86
To: Garrett D'Amore <>
From: Jared D. McNeill <>
List: tech-kern
Date: 05/08/2006 12:49:01
On Mon, 8 May 2006, Garrett D'Amore wrote:
> There's a bunch of Linux power management crapola in the video drivers.
> Sleep/wake is "especially" interesting, because some of these video
> parts have unique initialization considerations.  When running Xwsfb on
> non-PC hardware, we might need the underlying wsdisplay to do the
> initialization.

I have concerns about users of servers other than Xwsfb and how they will 
interact if we start buggering with various display registers while 
they're running. I'm sure we can work around them..

Anyway, wsdisplay already exposes an API for blanking the screen; we just 
need to extend it to support additional types of blanking (dim, sleep, 
suspend, etc).

> Looking at powerd, it looks like the way to go.  But I cannot find any
> really useful on kernel APIs.  The powerd manual page references ACPI
> man pages.  (I guess there is the powerhook(9) man info...)

powerd will certainly need to be extended to do what we need to do.