API to turn off the display

[John Baldwin]

On Thursday 29 January 2004 11:20 am, Mark Santcroos wrote:
> On Thu, Jan 29, 2004 at 01:21:28AM +0000, James Green wrote:
> > > > I find DPMS works for me..
> > > >
> > > > xset dpms force off
> > > >
> > > > My Monitor section in the X config has..
> > > >   Option      "DPMS"
> > > >
> > > > My video chipset is an ATI Rage 128 Mobility in a Dell Inspiron 8000.
> > >
> > > I use the above, one minor thing though, the backlight on the laptop
> > > stays on (NEC Versa S900 with ATI radeon 9000 mobility) yet under
> > > windows the backlight turns off, still haven't got it  worked out :/
> >
> > There is a fix for DPMS for the Radeon 9000. The bug report/patch etc.
> > is here: http://bugs.xfree86.org/show_bug.cgi?id=26
> > See comment #10 for details.
>
> ports/x11-servers/XFree86-4-Server-snap/ has the fix too, I just tried
> it and it works for my Latitude C640.
>
> Which leads me to think... can we do this with ACPI only or do we need
> to do what DPMS is doing?? I think it is the latter.

I read the spec yesterday, and what is supposed to happen is this:  The 
display (LCD, CRT, etc.) is supposed to be powered down using DPMS.  The 
actual adapter is then supposed to be powered down using either PCI or ACPI 
sleep states, and the adapter should not be powered down to a lower sleep 
state (like D3) w/o using DPMS to power the display down to at least that 
state first.  This means that the kernel might need to grow a dummy vga 
driver of some sort and some simple dpms support for suspend/resume.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org