From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH] phylib: fix forced mode misbehaviour for aneg off case Date: Thu, 3 Jul 2008 20:18:17 +0100 Message-ID: <20080703191815.GG17872@solarflare.com> References: <20080703171614.GA21126@polina.dev.rtsoft.ru> <20080703104143.6620e99f@extreme> <20080703181118.GA30139@polina.dev.rtsoft.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stephen Hemminger , Jeff Garzik , Andy Fleming , netdev@vger.kernel.org To: Anton Vorontsov Return-path: Received: from smarthost01.mail.mbr-roch.zen.net.uk ([212.23.3.140]:44896 "EHLO smarthost01.mail.zen.net.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752395AbYGCTSZ (ORCPT ); Thu, 3 Jul 2008 15:18:25 -0400 Content-Disposition: inline In-Reply-To: <20080703181118.GA30139@polina.dev.rtsoft.ru> Sender: netdev-owner@vger.kernel.org List-ID: Anton Vorontsov wrote: > On Thu, Jul 03, 2008 at 10:41:43AM -0700, Stephen Hemminger wrote: > > On Thu, 3 Jul 2008 21:16:14 +0400 > > Anton Vorontsov wrote: > > > > > With disabled autonegotiation and link absence, phylib will place phy > > > into the forcing mode, thus will start calling phy_force_reduction(). > > > That means that for the drivers that are using phylib we can't actually > > > set fixed speed for the link. > > > > > > For example: > > > > > > # ethtool -s eth0 autoneg off speed 1000 > > > > FYI autonegotiation is required in gigabit mode per 802 spec. This is technically correct, but all "negotiated" settings can be manually configured such that only a single possible configuration is advertised during auto-negotiation. > Thanks for the information. FWIW, that behaviour observed for > speed 100 or speed 10, too. > > As for gbit, this is interesting indeed. If we're not permitted to > disable aneg, how could we force the PHY to use gigabit, so that it > will not try to downgrade? I mean ethtool option. You should be able to use "ethtool -s eth0 autoneg on speed 1000 duplex full" (you have to specify all three). Not all drivers implement that correctly though. Ben. -- Ben Hutchings, Senior Software Engineer, Solarflare Communications Not speaking for my employer; that's the marketing department's job.