[ltp] ACPI S3 power drain and Thinkpad Wiki/radeonfb

[linux-thinkpad@linux-thinkpad.org]

Hi,

I'm trying to reduce the well-known ACPI S3 power drain problem on my
T40, and following the advice on the Thinkpad Wiki at:

http://www.thinkwiki.org/wiki/Problem_with_high_power_drain_in_ACPI_sleep

Firstly, I confirmed my model (T40 237392G) is affected by
downloading the sleep.sh script and running for 20 minutes on
battery.  Result:
Thu Jul 14 23:16:04 BST 2005
before: 16030 mWh
after: 14620 mWh
diff: -1410 mWh
seconds: 1356 sec
result: -3743 mW
Your model seems to be affected.

I'm using Fedora Core 4, and as stated on the site, confirmed that a
patch is included to fix this - it's called
linux-2.6.11-radeon-backlight.patch and having read through, I
confirmed my module isn't whitelisted.  No problem: I loaded the
radeonfb module (which isn't normally loaded) with:

# modprobe radeonfb radeon_force_sleep=1

in /etc/rc.local and booted, which should force it into suspend-to-D2
as I understand it anyway.

Disappointingly, the results from my next test were the same, with
very similar drain and "Your model seems to be affected.".  I went
the whole way, stopping X (init 3), loading the module and restarting
X, but again, it doesn't fix the drain problem.

Oddly whenever the module is loaded, I get the following in
/var/log/messages:
Jul 15 16:43:05 localhost kernel: PCI: Unable to reserve mem region
#1:8000000@e0000000 for device 0000:01:00.0
Jul 15 16:43:05 localhost kernel: radeonfb (0000:01:00.0): cannot
reserve PCI regions.  Someone already got them?
Jul 15 16:43:05 localhost kernel: radeonfb: probe of 0000:01:00.0
failed with error -16

I confess to not understanding what these mean.  The module however
loads ok (or at least appears in lsmod), and this seems to happen
whether I use the force option or not.

Can anyone shed any light on what might be wrong here, or where I can
look for help?  I don't want to swap from Fedora kernels, but maybe
there are some grub kernel boot options that may help?  I assume I'm
using vesafb, as I don't normally load radeonfb, and don't have any
special switches at boot, apart from requesting a higher resolution
with "vga=0x317".

Thanks!
Honey