S3 suspend on a Dell I8k laptop (ACPI)

[Sean Welch]

I thought that before I put in a pr I would check here to see if
anyone else has experienced this issue and if there is a
fix/work-around for it.  Apologies in advance for crossposting.

It has been some time since I tried to use S3 (I think the last time
was about 4.6-RELEASE or so) and I've never tried it with ACPI before
now.  I had swapped out the graphics card and that confused the BIOS
on resume causing a shutdown, but for various reasons I have now
replaced the original card and want to get suspend working again.

I've seen the typical "it comes back from suspend and then immediately
reboots" but found that this behavior goes away if I set: 

  hw.acpi.reset_video: 0

Likewise, on the console I get the screen showing all white during
suspend and on resume it turns the backlight off.  I can toggle it
back on using acpi_video sysctls for the lcd and the problem is
nonexistent if I suspend under X and issue a dpms command beforehand
to force the lcd off.

On the whole I'm quite pleased with the resume capability (I'm mostly
in X anyway) -- X, usb, mouse, pcmcia wireless, sound, keyboard, and
everything else come up flawlessly.  I discovered a potentially fatal
issue, though.  It appears the processor is running full throttle and
in suspension there is no cooling.  I'm lucky I noticed this last
night before I went to bed -- I might have ended up with a smoking
pile of molten electronics and quite possibly a fire.  By the time I
noticed it was very hot indeed and the electronics/plastics were
beginning to outgas...

I quad boot the machine (WinME, FBSD 5.3R, FBSD 5.4R, FBSD 5.4R) and
the behavior is the same under both 5.3R and 5.4R (other than fxp0
dying under 5.3R).  WinME isn't giving me an option for anything other
than StandBy at the moment so I can't test it there though it seemed
to work fine when I triggered it from DOS (booted from floppy).  I
have a custom kernel under 5.3 and just GENERIC under 5.4 (haven't
configured it yet).  My first thought was that the hlt instruction
wasn't being issued but a quick check brings up:

  machdep.cpu_idle_hlt: 1

Can anyone offer advice?  I'm running the latest revision of the BIOS
(A23) and will be happy to post the asl on request.

Sean