Re: Resume -> higher power drain?

[Dominik Brodowski <linux-X3ehHDuj6sIIGcDfoQAp7OTW4wlIGRCZ@public.gmane.org>]

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Hi,

On Sat, May 07, 2005 at 04:14:56PM +0200, Hendrik Jürgens wrote:
> Am Samstag, den 07.05.2005, 15:59 +0200 schrieb Carl-Daniel Hailfinger:
> > Hi,
> > 
> > Nils Faerber schrieb:
> > > I just observed a strange phenomenon on my new T42p (latest BIOS).
> > > [...]
> > > Before suspend I usually see a power consumption of about 16W including
> > > WLAN, which is nicely low.
> > > But strangely after resume from either S3 or S4 I have see a power
> > > consumption of 19W+. This means ~3W more or in other words, roughly 20%
> > > less runtime.
> > 
> > I didn't measure the power consumption of my Samsung P35, but after
> > resume from S3 it gets hotter under the same load than before suspend.
> > So I can somewhat confirm your report.
> > 
> I can also confirm this behaviour with my acer tm4002lmi. it also has ja
> power consumption ~16W and after resuming it has round about 20W.

On a P35, a friend of mine determined that suspend to mem leads to a higher
power consumption if X was running. But only when using the ATI driver. When
using the vesa driver, the power consumption is increased to a higher rate 
all the time...

Other than the video driver, you can check whether PCI devices changed their
status (they shouldn't) by doing "lspci -vvv > lspci_before.txt" before
suspend, "lspci -vvv > lspci_after.txt" after suspend, and checking 
"diff -u lspci_before.txt lspci_after.txt".

Also, does the bus master activity rates typically seen (check 
/proc/acpi/processor/*/power every once in a while) differ
between pre-suspend and post-suspend?

	Dominik

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