[ltp] Success w/ kernel 2.6+ACPI and swsusp hibernation on t41 (no-X)

[Rob Browning]

I decided to try kernel 2.6 (test11), ACPI, and swsusp hibernation in
addition to my earlier test with 2.4.22 and PhoenixBIOS suspend, and I
was surposed to find that it seems to work.  "echo 4 >
/proc/acpi/sleep" puts the machine into hibernation, and if you have
the right "resume=/dev/WHATEVER" kernel argument set up in grub (or
whatever you boot with) the machine will pick up where it left off
when you power it back up.

There is one (possibly known) glitch, though.  After the image is
written to swap, the screen goes blank, but the power light stays on
until you hold down the power button for several seconds.  At that
point the machine will finally power down completely.  I suppose this
could be because I'm not using the swsusp hibernate script, but just
running "echo proc" directly.

The swsusp suspend is *much* faster than the PhoenixBIOS (apm) suspend
arrangement that I tested earlier, but I'm still not sure what
interaction the swsuspend based hibernation might be able to have (if
any) with the laptop's BIOS Power settings, suspension (as opposed to
hibernation), or the keys like Fn+F12.  As far as that's concerned,
the earlier 2.4+PhoenixBIOS arrangement was better, since suspend and
hibernate both worked, and suspend respected at least the RediSafe
BIOS settings (I didn't test any of the others -- i.e. the timers, etc.).

(Again, bear in mind that this is on a machine with (as yet) no X.)

-- 
Rob Browning
rlb @defaultvalue.org and @debian.org; previously @cs.utexas.edu
GPG starting 2002-11-03 = 14DD 432F AE39 534D B592  F9A0 25C8 D377 8C7E 73A4