APM or ACPI or both?

Message

alexander-m · Post by **alexander-m** » Mon Aug 30, 2004 11:38 pm

Hi I'm installing gentoo on a notebook and I am therby searching for a Power Management.

The 2.6x Kernel provides APM and ACPI support.

I wanna use these features of my laptop:

* cpu throttling
* suspend-to-disk (hibernate)
* suspend-to-ram (standby)

What PowerManagement (APM or ACPI) would you recommend in general and
if so please tell my the reason that lead you to this decision

Thanks in advance

Alexander

G3n2 · Post by **G3n2** » Tue Aug 31, 2004 12:10 am

I'm compiling my kernel atm for my Acer Aspire with both ACPI and APM in the kernel , i dont know if this is a problem.

-G3n2

Archangel1 · Post by **Archangel1** » Tue Aug 31, 2004 12:55 am

As far as I know ACPI is newer and the way things are going. I'm not sure if CPU speed adjusting works via APM/ACPI or if it's independent of them.

For hibernate, you need to patch your kernel with some additional stuff - software suspend 2 seems to be the best. It's at swsusp.sf.net.

searcher · Post by **searcher** » Tue Aug 31, 2004 1:00 am

Choosing both ACPI and APM at kernel compile time will default to ACPI when you boot the kernel, since this is the newer one. For older pc's you'll probably want APM, for newer ones ACPI.

~searcher

snekiepete · Post by **snekiepete** » Tue Aug 31, 2004 1:03 am

plus if your laptop has hyperthreading and you enabled smp in the kernel, apm will not work.

Phage64 · Post by **Phage64** » Tue Aug 31, 2004 4:12 am

you can compile both acpi and apm into the kernel but whichever loads first is used and the other isn't. You can specify at boot which to use with something like "acpi=on apm=off"... as for software suspend you will want to look at the swsusp patch but I'd prefer to switch my system off to using it... acpi isn't completely supported but most of the features work using the 2.6.8-r3 kernel (gentoo-dev-sources). Frequency scaling doesn't require either ACPI or APM unless you have a Dothan and then it requires ACPI unless u patch the kern... hope that helps

alexander-m · Post by **alexander-m** » Tue Aug 31, 2004 7:12 am

For hibernate, you need to patch your kernel with some additional stuff - software suspend 2 seems to be the best.

Just wanted to verify that I really have to patch my kernel , what is somesimng undesireable new for me

I currently use the 2.6x kernel
eg 2.6.8.r3 gentoo-dev-sources
Do I really have to patch this kernel or is the patch for older ones?
cause, I already can choose [*] suspend-to-disk support in the Power Management section
of my kernel config

thanks for all the answer who already helped me a lot.

Alexander

Phage64 · Post by **Phage64** » Tue Aug 31, 2004 12:26 pm

You really do have to patch the kernel... the built in software suspend is not as complete as swsusp2. The built-in code is based off of swsusp1. You can try the built in software suspend and maybe get luckyl