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Date: Sat, 19 Dec 2009 23:31:22 +0000
Message-ID: <3ace41890912191531k8703ecfr19c33f30127b2ecb@mail.gmail.com>
Subject: Re: Power consumption of RTL8187 (driver)/recommendations for
	low-power USB 802.11 adapter?
From: Hin-Tak Leung <hintak.leung@gmail.com>
To: Florian Zumbiehl <florz@florz.de>
Cc: Andrea Merello <andreamrl@tiscali.it>,
	Larry Finger <Larry.Finger@lwfinger.net>,
	herton@mandriva.com.br, htl10@users.sourceforge.net,
	linux-wireless@vger.kernel.org
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Sender: linux-wireless-owner@vger.kernel.org

On Sat, Dec 19, 2009 at 6:44 PM, Florian Zumbiehl <florz@florz.de> wrote:

> So, a base load of 3.8 W seems to be caused by any connected usb device
> preventing C3 and some 250 ms polling done by uhci_hcd, plus a bit for
> the device itself. According to
> http://www.mail-archive.com/linux-usb-users@lists.sourceforge.net/msg19354.html
> (why aren't there any message IDs on any of those archive sites, BTW?)
> that's the expected behaviour.

Presumably power-management changes have a time granuarity i.e. if you
make the CPU busy for one moment, it would stay in the higher-power
state for a while before dropping down? That's the standard thing to
do for prevent the power state being changed too often (and have bad
effects of some sort)?