Power-drain during suspend?

Kevin Oberman oberman at es.net
Thu Feb 9 08:34:41 PST 2006


> Date: Thu, 09 Feb 2006 11:07:44 +0100
> From: Gregers Petersen <gp.ioa at cbs.dk>
> Sender: owner-freebsd-mobile at freebsd.org
> 
> Dear all
> 
> I'm running FreeBSD 6.0 Release on an IBM Thinkpad R51, with a Ati 9000 
> GPU and have problems with a very high power comsumption during suspend?
> All other issues have been solved and everything is working and stable 
> (speedstep, lid-suspend, buttons, wifi, network/mouse after suspend 
> etc.) -  I have aprox. 2.5 hours when I run on battery - but if I send 
> the R51 into suspend (S3) the battery is completely drained after 6-7 hours?
> I have been trying to add 'Radeontool' to my suspend/resume scripts - 
> but this does not solve the problem.
> 
> 
> Would anybody be able to advice me on this subject ?

Sure. It's free and probably worth about that, but:

Since you are using RadeonTool, are you just turning off the LCD screen?
Yo also should turn off the DAC which is used to drive the VGA
connector.
# If radeontool is available, turn off the light
if [ -x /usr/local/bin/radeontool ]; then
        /usr/local/bin/radeontool light off
        /usr/local/bin/radeontool dac off
fi

I don't bother to turn the DAC back on whenI resume, since I really
don't ever use it.

Another big issue is setting the power states of PCI devices. While
support for this has been in FreeBSD for a while (6.0?), the application
of them on some platforms, usually desktops, results in lock-ups. As a
result, parts are disabled by default. Most laptops have no problems
implementing this capability and turning it on should improve things, as
well.

hw.pci.do_power_nodriver=[1|2|3]

The larger the number, the more aggressive the power limitations. I use
'3' on my T30 and it works fine.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634


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