From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: Lower wake up time when phy enter lower mode Date: Fri, 9 Nov 2012 15:07:19 +0000 Message-ID: <1352473639.3159.3.camel@bwh-desktop.uk.solarflarecom.com> References: <1352315183.2725.17.camel@bwh-desktop.uk.solarflarecom.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Richard Cochran , To: Frank Li Return-path: Received: from webmail.solarflare.com ([12.187.104.25]:33793 "EHLO ocex02.SolarFlarecom.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753527Ab2KIPHZ (ORCPT ); Fri, 9 Nov 2012 10:07:25 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2012-11-08 at 10:09 +0800, Frank Li wrote: > 2012/11/8 Ben Hutchings : > > On Wed, 2012-11-07 at 10:52 +0800, Frank Li wrote: > >> Richard: > >> > >> Recently, I found out the path delay will increase about > >> 20us suddenly in something when connect two iMX6 board and Ethernet > >> work on 1G mode. > >> The reason is that the PHY enter lower mode automatically > >> when no package send and receive. It takes some time to recover and > >> send out package by PHY but MAC think package have sent and sample > >> time stamper. > >> Do you meet such case? I can workaround it by two method > >> 1. disable phy lower power feature. > >> 2. add some dummy package before SYNC package. > > > > If this low power mode is related to EEE (Energy Efficient Ethernet) > > then there are ethtool operations defined for configuring it, and you > > could implement those. > > Yes, it is phy specific, called smart EEE, which compatible with IEEE 802.3az > and can be used in legacy MAC without EEE. > > Do you have example about ethtool operations? Look at the comments on struct ethtool_eee in , and the existing implementations: drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.