Re: 2.6.13-rc3 Battery times at 100/250/1000 Hz = Zero difference

From: Bill Davidsen
Date: Mon Jul 25 2005 - 14:02:01 EST

Tony Lindgren wrote:
* Voluspa <lista1@xxxxxxxxx> [050722 11:46]:

On Fri, 22 Jul 2005 20:02:36 +0200 Pavel Machek wrote:

will not help. It seems like your machine is simply not able to do
reasonable powersaving.

Digging up this patch from last month regarding C2 on a AMD K7 implies
that the whole blame can be put on kernel acpi:

AFAIK Linux ACPI expects BIOS to contain all the necessary stuff to enable
C2 and C3. Otherwise they won't get enabled, and you have to create a custom
module like the amd76x_pm is.

Does that imply that Windows actually has such non-BIOS code, or just knows how to find the BIOS code better, or knows how to do other things, or ???

There's been some talk on adding a module to enable C2 and C3 states for
various chipsets, but nobody seems to have enough time to do it...

I like your first thought better, "Linux ACPI expects BIOS to contain all the necessary stuff" I have a bunch of laptops of various ages, and I would expect at least the most recent, an ASUS 16??, using a "Centrino" chipset, to be supported. It's one of the top few laptopl chipsets, and Windows can suspecd it. Can also not only detect but use the 1400x1050 screen, but that's another issue :-(

Is it possible that the code to find these capabilities is not fully functional? That seems more likely than the system not having the capability. NOTE: "seems" as in experienced guess unsupported by other relevant information.

-bill davidsen (davidsen@xxxxxxx)
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me

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