From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.ebshome.net (gate.ebshome.net [208.106.21.240]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (Client CN "gate.ebshome.net", Issuer "gate.ebshome.net" (not verified)) by ozlabs.org (Postfix) with ESMTP id 15186DDD08 for ; Tue, 13 Feb 2007 13:40:18 +1100 (EST) Date: Mon, 12 Feb 2007 18:40:15 -0800 From: Eugene Surovegin To: Lonsn Subject: Re: How to force the 1000M network interface work in 100M mode?(AMCC 440GX, board based on ocotea) Message-ID: <20070213024015.GD9754@gate.ebshome.net> References: <45D123A9.50805@126.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <45D123A9.50805@126.com> Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Feb 13, 2007 at 10:34:17AM +0800, Lonsn wrote: > Hi, all: > We have design a new board based on AMCC ocotea board. The linux kernel > version we use is 2.6.18 from kernel.org. The network interface is the > same as ocotea(eth0 and eth1 work in SMII mode, eth2 and eth3 work in > RGMII mode).The 1000Mbit ehernet physical transceiver chip is also > CIS8201(VSC8201). These pins(ANEG_DIS,FRC_DPLX,MODE10,MODE100,MODE1000) > of CIS8201 are set as 01111. > Maybe because of the signal integrity problem of the gigabit > clock&data,eth3 doesn't work in 1000M mode(eth2 is ok). If we connect > eth3 with a host which has 100M ethernet, then eth3 works in 100M mode > well. If we connect eth3 with a host which has 1000M ethernet interface, > then eth3 can recognize the link is 1000Mbit, but ping is not ok. > So we want to force the eth3 work in 100M mode even eth3 is connected > with a 1000M host.(we think the hardware is ok when eth3 works in 100M > mode). > We have used ethtool in the board and in the host to force the eth3 work > in 100M mode, but failed. Maybe we can't change this setting in > userspace? or we should changed the IBM_EMAC driver? > Any suggestions? Use ethtool to limit advertised auto-negotiation mode or force 100 on _both_ ends of the link. Probably, when you forced 100, you did it only on 440GX side, that's why it failed. Personally, I prefer "forcing" link speed by tweaking advertised modes, this way you have to do this only on one side of the link. -- Eugene