"deeper sleep mode" support in -STABLE?

[Brad Karp]

Hello, all.

I read Marko Zec's post to -mobile with great interest:

http://www.freebsd.org/cgi/getmsg.cgi?fetch=176046+181234+/usr/local/www/db/text/2003/freebsd-mobile/20031019.freebsd-mobile

This post offers a nifty patch to use the new "deeper sleep" mode supported
on P-III-M, IV-M, and "Centrino" Pentium Mobile processors. Marko reports
that he gets 18% additional battery life with the LCD on using this mode
vs. the "HLT" idle loop method used in -STABLE today, and 22% longer life
with the LCD off.

The patch he posted:

http://www.tel.fer.hr/zec/BSD/pm/4.8-ich-ds.patch

Have others tried his patch and had good luck with it? I've got a ThinkPad
X31, and am considering giving it a go. I presume it will apply reasonably
cleanly to 4.9-RELEASE, though I've not tried yet.

Also: are any committers looking at this patch for inclusion in either the
-STABLE or -CURRENT branches? (Or does ACPI achieve the same power savings
that this patch does?)

Many thanks to Marko for passing this patch along!

-Brad, bkarp at cs.cmu.edu