API to turn off the display

[Randy Bush]

> I have found that too. I did most of my testing over ssh, until I setup
> a serial login console (boot -h, and appropriate line in /etc/ttys) , so
> I could see any messages that I might be missing... and I could not
> reproduce the hang. Suspended without any problem at all. Tried booting 
> with the -h and I could reproduce the hang every time.
> 
> Recompiled the kernel with:
> options SC_NO_SUSPEND_VTYSWITCH
> 
> and now it all works!
> 
> I added to rc.suspend:
> 
> xset -display :0 dpms force off
> sleep 3
> sysctl hw.acpi.video.lcd0.active=0
> sleep 1
> sysctl hw.acpi.cpu.throttle_state=1
> 
> and to rc.resume:
> 
> sysctl hw.acpi.cpu.throttle_state=8
> xset -display :0 dpms force on
> sysctl hw.acpi.video.lcd0.active=1
> 
> The order of DPMS and ACPI is important. This works on both the console
> and in X. Next up is to add in ataidle...

this helps a LOT.  but ...

i can suspend once and resume once.  after that, it will not suspend
with lid or button.

randy