ACPI S3 suspends works, at last!

[tv123]

Hi folks,

I have recently purchased a Dothan centrino tablet pc, and have
quickly discovered that the good ol' "apm -s" no longer works
on newer laptops.

After wasting a good bit of time fixing DSDT tables etc, I finally
found out a way get ACPI S3 suspend (supending to RAM) to work
on my pc, thanks to Ubuntu's outstanding linux distribution!!
(My favorite full linux distros of all time: RH 6.1/6.2, Knoppix 3.3/3.4,
recent Kanotix, recent Ubuntu).

Here is the recipe that works for me:

1) Install a daily Ubuntu snapshot (mine is from 1/22/05, kernel: 2.6.10-2-386).

2) Add these lines to /etc/apt/sources.list so that you can access the source
and binaries for the "video_post" utility, written by some Intel chap:

#ACPI
deb http://www.srcf.ucam.org/~mjg59/laptops/ ./
deb-src http://www.srcf.ucam.org/~mjg59/laptops/ ./

2) Download video_post source to some folder, build it, and install it:

apt-get source --build video-post
dpkg -i video-post_0.1-1_i386.deb

3) comment out the line "" /sbin/shutdown -h now "Power button pressed" ""
in /etc/acpi/powerbtn.sh, as this this gets triggered when trying to
resume using the power button, and it starts the shutdown sequence then.

4) add options "noapic" and "nolapic" to the kernel line in the grub stanza
that boots this ubuntu install (not sure if these are really needed, but I had
read somewhere that this helps). Here is the kernel command line (change it to
suit your setup)

root=/dev/hda* ro quiet splash resume=/dev/hda* noapic nolapic

5) Reboot to make sure these options take effect.

6) create the script /sbin/ZZ:
#!/bin/sh
echo "mem" > /sys/power/state
# restart your kernel graphics module, if necessary
# modprobe i915 # my video card is Intel Extreme Graphics chipset
/usr/sbin/video_post

7) Do "chmod 775 /sbin/ZZ", and "sudo /sbin/ZZ". This should put your pc
to sleep, hopefully temporarily

To resume, do what ever it is that you do to resume from hibernation under
windows, such as "jogging" the power button. You should get a blank BACKLIT
screen (presumably due to the use of "video_post", which is meant for console
use, but without it, the screen never wakes up after resume).

9) Do "Ctrl-Alt-F1", which should take you to the first console screen. Then do
"Ctrl-Alt-F7", and that should bring you back to Gnome. Directly switching to
graphics screen fails for me.

10) FInally, if you suspend and close the lid, then reopening the lid
trigger the resume sequence, and in this it seems to go straight to
the graphics screen.

Good luck with the recipe, and please post your success or failure with
details so we can try and help you out.

Thanks,
Tom