Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753516AbbBFLBI (ORCPT ); Fri, 6 Feb 2015 06:01:08 -0500 Received: from eddie.linux-mips.org ([148.251.95.138]:46756 "EHLO cvs.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751168AbbBFLBE (ORCPT ); Fri, 6 Feb 2015 06:01:04 -0500 Date: Fri, 6 Feb 2015 11:01:02 +0000 (GMT) From: "Maciej W. Rozycki" To: Pavel Machek cc: kernel list , netdev@vger.kernel.org Subject: Re: Ethernet: how to disable gigabit support In-Reply-To: <20150205202527.GA7917@amd> Message-ID: References: <20150205202527.GA7917@amd> User-Agent: Alpine 2.11 (LFD 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1969 Lines: 51 On Thu, 5 Feb 2015, Pavel Machek wrote: > This happened on more than one project: there's gigabit-capable chip, > but the connector is not designed for gigabit speed. > > I'd like to have speed autonegotiation, but not offer gigabit (as it > will not work). > > Is there way to do that without hacking the kernel? Should mii-tool do > that? It used to work for me with a 3Com 3c905C adapter when I needed to force full duplex for an old non-negotiating 100baseTx-FD network switch. > root@ib8315:~# mii-tool.net-tools -A 100baseTx,10baseT eth1 > restarting autonegotiation... > root@ib8315:~# [32432.443883] libphy: mdio@e0024520:01 - Link is Down > > root@ib8315:~# [32435.447863] libphy: mdio@e0024520:01 - Link is Up - 1000/Full > > root@ib8315:~# mii-tool.net-tools -v eth1 > eth1: negotiated 1000baseT-FD flow-control, link ok > product info: vendor 00:01:c1, model 3 rev 1 > basic mode: autonegotiation enabled > basic status: autonegotiation complete, link ok > capabilities: 1000baseT-FD 100baseTx-FD 100baseTx-HD > 10baseT-FD 10baseT-HD > advertising: 1000baseT-FD 100baseTx-FD 100baseTx-HD > 10baseT-FD 10baseT-HD > link partner: 1000baseT-FD 100baseTx-FD 100baseTx-HD > 10baseT-FD 10baseT-HD flow-control > root@ib8315:~# mii-tool.net-tools -V > $Id: mii-tool.c,v 1.9 2006/09/27 20:59:18 ecki Exp $ > (Author: David Hinds based on Donald Becker's mii-diag) > net-tools 1.60 > root@ib8315:~# You may have to spell out media names in full, e.g.: # mii-tool -A 100baseTx-FD,100baseTx-HD,10baseT-FD,10baseT-HD eth1 Also the driver may have a way to override the capabilities advertised via a module parameter. This is what I eventually ended up with with the 3c905C adapter. Maciej -- 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/