From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next 0/8] bnx2x: Minor link related fixes Date: Wed, 01 Sep 2010 12:01:37 -0700 (PDT) Message-ID: <20100901.120137.84370412.davem@davemloft.net> References: <1283370674.4403.131.camel@lb-tlvb-yanivr.il.broadcom.com> <20100901.104524.216750458.davem@davemloft.net> <1283366622.5874.1.camel@lb-tlvb-eilong.il.broadcom.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: yaniv.rosner@broadcom.com, netdev@vger.kernel.org To: eilong@broadcom.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:38605 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755212Ab0IATBV (ORCPT ); Wed, 1 Sep 2010 15:01:21 -0400 In-Reply-To: <1283366622.5874.1.camel@lb-tlvb-eilong.il.broadcom.com> Sender: netdev-owner@vger.kernel.org List-ID: From: "Eilon Greenstein" Date: Wed, 1 Sep 2010 21:43:42 +0300 > On Wed, 2010-09-01 at 10:45 -0700, David Miller wrote: >> Can you explain why 10mbit/100mbit links have to use forced link mode >> and do not use autonegotiation by default? I could understand for >> 10mbit but 100mbit too? >> > Our understanding of the requirements is that if the user selects force > speed of 1G or higher, it is recommended to use autonegotiation with > only that speed advertized. However, when the user selects force speed > of 10M or 100M, assuming the other side is actually forcing the speed, > using autonegotiation will fail and fall back to parallel detect and > that will establish link in HD mode (as required) while the other side > is likely to be using FD this will cause duplex mismatch and many > errors, so it is best to keep 10M/100M truly forced to support older > link partners. I see, thanks for the explanation.