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: Wed, 7 Nov 2012 19:06:23 +0000 Message-ID: <1352315183.2725.17.camel@bwh-desktop.uk.solarflarecom.com> References: 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]:60342 "EHLO ocex02.SolarFlarecom.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754106Ab2KGTG0 (ORCPT ); Wed, 7 Nov 2012 14:06:26 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: 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. 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.