IBM ThinkPad T42 problems with ACPI

[Julien Poissonnier]

IIRC, windows first goes to standby (acpi state 3, most hardware powered 
off, except RAM), then after an hour or so it goes to suspend (acpi 
state 4, windows calls this hibernate, writes RAM to disk, completely 
powers off)
Unfortunately, suspend isn't enabled in the Ubuntu kernel and it heavily 
depends on the laptop if it is even possible to get it to work, most 
Thinkpads have a good track record, though... and getting standby to 
work is ususally more difficult than suspend, ah how I wish I had an IBM 
T4x instead of this Acer Travelmate :)

Tim Hull wrote:
> I installed Ubuntu on an IBM ThinkPad T42.
> Just about everything works great (including wi-fi!), and the
> whole system is very stable.  However, I am having one nagging problem 
> with ACPI.  I set up a basic script to put the laptop into suspend when
> I close the lid that removes ehci_hcd (which prevents a suspend) removes 
> my hsf winmodem drivers, and then puts the laptop into suspend with a 
> echo 3 > /proc/acpi/sleep.
> While this works, my laptop gobbles HUGE amounts of battery while in 
> suspend (about 10% of the battery per hour!) and I can't figure out 
> why.  I know it is suspended (the suspend light is on, and all the 
> drives/fans were off) but something is wrong.  In Windows, suspend works 
> fine.  If I use APM, I can suspend fine  without gobbling battery but my 
> laptop is much more hot (as speedstep is incompatible with APM), and 
> gets worse battery life.  Does anyone have a solution to this?  It has 
> happened with every distribution I've tried.
>