Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932745AbXJQNAp (ORCPT ); Wed, 17 Oct 2007 09:00:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1765189AbXJQNA1 (ORCPT ); Wed, 17 Oct 2007 09:00:27 -0400 Received: from caffeine.csclub.uwaterloo.ca ([129.97.134.17]:54347 "EHLO caffeine.csclub.uwaterloo.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764998AbXJQNA0 (ORCPT ); Wed, 17 Oct 2007 09:00:26 -0400 Date: Wed, 17 Oct 2007 09:00:25 -0400 To: "Kok, Auke" Cc: Valdis.Kletnieks@vt.edu, 7eggert@gmx.de, prasad@linux.vnet.ibm.com, Pavel Machek , Arjan van de Ven , kernel list Subject: Re: gigabit ethernet power consumption Message-ID: <20071017130025.GN4000@csclub.uwaterloo.ca> References: <9c8XH-7gs-13@gated-at.bofh.it> <9c9qN-7Rn-19@gated-at.bofh.it> <9cs0n-3Dc-9@gated-at.bofh.it> <9csjH-43E-33@gated-at.bofh.it> <9d4yC-5hT-7@gated-at.bofh.it> <9d7ZJ-2mI-11@gated-at.bofh.it> <470FA243.6030908@intel.com> <12419.1192221016@turing-police.cc.vt.edu> <470FDD29.9030708@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <470FDD29.9030708@intel.com> User-Agent: Mutt/1.5.13 (2006-08-11) From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1080 Lines: 22 On Fri, Oct 12, 2007 at 01:46:33PM -0700, Kok, Auke wrote: > I would assume that that is true for all PHY's - if there is no link to keep the > carrier active on I would think that the power consumption is nominal across the > board. Once the PHY detects link pulses it should obviously use different power > levels to negotiate the link for each speed. > > PHY autonegotiation just works the same across the board - the PHY's send out > little pulses (iow nominal power consumption) to detect a link partner, and only > when one is found do they engage in more aggressive conversation to establish > capabilities across the link. Too bad not much can be done about fibre ports, but then again you can't even change speeds on those. Then again those are not on laptops or other low power devices in the first place. -- Len Sorensen - 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/