Power-drain during suspend?

Kevin Oberman oberman at es.net
Fri Feb 10 10:21:50 PST 2006


> From: Randy Bush <randy at psg.com>
> Date: Fri, 10 Feb 2006 07:53:32 -1000
> 
> >>> 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.
> >> in rc.suspend, or where?
> > Use sysctl(8) to set it for testing.  If it works, you can then make  
> > it permanent by setting it either in /boot/loader.conf or /etc/ 
> > sysctl.conf.
> 
> so, it's a running state.
> 
> how do i know "if it works?"

If it does not work you will most likely see your system lock up.

I believe that some SCSI controllers may have problems with it in
FreeBSD. It's not clear to me whether this is a FreeBSD driver problem
or a hardware/firmware issue. 

I have never had it fail but have seen reports that it does on some
systems and that's why it is disabled by default. Since the reported
problems have been with disks, I suppose it's possible that the lock-up
won't happen until the problem driver/device is used. If the disks can't
be accessed, it's kind of obvious that there is a problem. :-)
-- 
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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