[ltp] X60: Off is *not* off ;)

[Nils Faerber]

Hi!
Some days ago I reported that my X60 drains battery even in off mode. I
did some very painful analysis...

Since Lenovo refused service for non-Windows systems I backed-up Linux
and installed XP.
Guess what? It did not drain the battery in off mode!

So I started to wonder...
I have to start with saying that I use suspend to disk...
First difference I found was that if I suspend to disk and have the AC
still connected the ethernet PHY was still active (LEDs blinking). This
did not happen with WinXP. When AC is disconnected the LEDs go off but I
thought, well, if threre is a difference there then there might be more
and some even with AC disconnected.
After some more searching I found that one can specify the off method
after suspend to disk - in the sys entry /sys/power/disk - Who did
invent that name? Well, anyway, after changing this from "platform"
(ACPI shutdown method) to "shutdown" (hard power off?) the LEDs were off
with AC connected after suspend to disk.
So I thought - hey, I got it!
Far from it. After 48h the battery lost 60%! In off mode!

I got quite upset about Linux, this notebook and the world in general.
And I felt especially bad since WinXP didn't show drain :(

So last night I tried the ultimate test - braindead as it seemed: I did
not use suspend to disk but did do a shutdown - at 97% battery.
Today I rebooted the machine and guess what? Still 97%!

So this leads me to two new insights:

1. There are oviously at least three power off methods! Not that off
would be simply off, no no. There is half off with PHY active with AC,
then there is drain-off and there is real off-off.
What a mess!

2. The power-off method in Linux is broken! Why does suspend to disk not
use the same power-off method as a shutdown?

And a question:
How can I tell suspend to disk to use the off-off method???
Obviously "platform" and "shutdown" (/sys/power/disk) do not do the
trick. But I also want to use suspend to disk by all means - it is a
major pain to restart all my apps etc. And I don't want to use suspend
to RAM because I don't care about some seconds delay at resume but I
care about my battery (and I don't want to drain it completely if I
don't use the machine for several days) - oh, and in planes, where it
should be off not suspended (well, actually nobody would care...).

Oh well...
So this was for the records... or if someone knows how to tell S2D to
use the real off-off mode I would be glad to hear it...

Cheers
  nils faerber

-- 
kernel concepts GbR        Tel: +49-271-771091-12
Sieghuetter Hauptweg 48    Fax: +49-271-771091-19
D-57072 Siegen             Mob: +49-176-21024535
--