Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932093AbWIXVFm (ORCPT ); Sun, 24 Sep 2006 17:05:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932100AbWIXVFm (ORCPT ); Sun, 24 Sep 2006 17:05:42 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:34520 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S932093AbWIXVFm (ORCPT ); Sun, 24 Sep 2006 17:05:42 -0400 Date: Sun, 24 Sep 2006 23:05:27 +0200 From: Pavel Machek To: Alan Stern Cc: kernel list , Greg KH , Linux usb mailing list Subject: Re: [linux-usb-devel] usb still sucks battery in -rc7-mm1 Message-ID: <20060924210527.GG1873@elf.ucw.cz> References: <20060924090858.GA1852@elf.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1789 Lines: 39 Hi! > > I made some quick experiments, and usb still eats 4W of battery > > power. (With whole machine eating 9W, that's kind of a big deal)... > > > > This particular machine has usb bluetooth, but it can be disabled by > > firmware, and appears unplugged. (I did that). It also has fingerprint > > scanner, that can't be disabled, but that does not have driver (only > > driven by useland, and was unused in this experiment). > > > > Any ideas? > > The USB autosuspend patches are still not entirely in -mm. They contain a > couple of bugs that have to get fixed first. When they do get merged you > should see considerable improvement. Note that although they will reduce > the amount of power being used by the USB controllers and will stop the > DMA activity (thus allowing your CPU to enter C2), they won't put the > controllers into D3. For that you'll have to get PCI autosuspend... > :-) I have not measured that, but I _hope_ drain by controller itself will not be big enough. > In the meantime, if all you care about is power consumption there are > some things you can do. The easiest is simply to rmmod ehci-hcd, > ohci-hcd, and uhci-hcd. After all, if you're not using USB there's no > reason to let the drivers eat up memory, CPU time, and power. Are autosuspend patches available somewhere? (Relative to -mm, or relative to 2.6.18?) I'd like to play with them... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/