[ltp] Re: How to turn your T42p into a brick with ACPI...

[linux-thinkpad@linux-thinkpad.org]

On Sun, 10 Apr 2005, David A. Desrosiers wrote:

> 	45 seconds to boot from a cold, powered-off machine? That's
> pretty accurate.
>
> 	If you mean 45 seconds to come out of suspend, that's
> absolutely unacceptable. It takes 2-3 seconds for my laptop to come
> out of suspend from apm, and another 1-2 seconds for network to return
> (I don't have to unload or reload any drivers, it "Just Works(tm)").

You're misunderstanding.  The APM suspend you're talking about is a
suspend-to-ram - it still requires and uses residual battery power
to keep its saved state, and won't last forever.  Swsusp2 provides
suspend-to-disk - complete power off with state saved as long as
you like.  It's primary advantage, to me anyway, is that it *saves
state* not just that it's quick.  As someone else said, you don't
need to login and start everything up again.

Swsusp2 typically takes about 10 seconds to suspend on my 1GB RAM
T40.  The longer time (30?) on startup is that it has to go through
BIOS restart and grub (obviously).

You can also enable suspend-to-disk in APM by allocating a special
partition type: you'll find it takes a whole lot longer than swsusp2.

If you only want suspend-to-ram, you can do this with ACPI without
swsusp2, and practically instantaneously.

> 	If it requires kernel patches, forget it. Does it work with
> stock, standard kernels, out of the box? I'm typically using daily
> kernels, because I need to track changes in the usb and driver
> subsystems for my development work on pilot-link and other projects.

Swsusp2 is considered too experimental for most vendors and the
kernel.org mainstream (although I find it very stable).  You'll need
to rebuild most (all?) vendor kernels if you want it, yes.  If it
happens to be Fedora, try this:

http://www.suspend2.net/fedora/

Honey