[ltp] Why use acpi for suspend?

[Frederik Wagner]

On Thu, 16 Sep 2004, Nick Bower wrote:

>Thanks, that's news to me - I assumed the bios was doing the suspend as
>I've never configured APM, and apmd is not running (although I'll admit
>that it is installed now that I've checked).

In principle for apm the bios _is_ doing the suspend work. With acpi
the OS is responsible for all the stuff...

>
>I installed tpb and perhaps this may be triggering apm for a suspend?  I
>can't think how else the FN+F4 could be intercepted.  I guess I should
>try and configure tpb work with acpi then.

AFAIK the some of the Fn combinations are handelt by the bios anyway.
They alway produce an event (also for acpi) for all the other
combination, which are not working out of the box, install the
great ibm_acpi module, which came up some weeks ago... And don't
forget the newest acpi kernel patch...

>
>On Thu, 2004-09-16 at 10:04, Frederik Wagner wrote:
>> Hi Nick,
>> 
>> >I've been reading people using acpi to suspend - why would I want to use
>> >this if suspend is working when I set the kernel boot parameter acpi=off
>> >and the battery monitor is working etc?  Obviously there is something
>> >I'm missing.
>> 
>> The problem using apm (this is what you are doing, when you disable
>> acpi) is, that you don't have the processor state C3 which saves quite
>> a lot more of power when the cpu is idle. Keeps my TP running longer
>> on acpi than on apm (when on battery). And switching from acpi to apm
>> just to suspend would be counterproductive... :-)
>> Suspend to disk is anyway possible with swsusp2. Works quite well...

Frederik!