From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Jacob Muller Subject: r8169 and flapping links Date: Wed, 13 Mar 2013 02:05:34 -0400 Message-ID: <5140172E.1030605@adam.gs> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from adam.gs ([64.188.63.86]:52989 "EHLO acheron.adam.gs" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752187Ab3CMGPU (ORCPT ); Wed, 13 Mar 2013 02:15:20 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) by acheron.adam.gs (Postfix) with ESMTP id 8B383D01E18 for ; Wed, 13 Mar 2013 02:05:35 -0400 (EDT) Sender: netdev-owner@vger.kernel.org List-ID: Hi, I have a pair of RTL8168B-based network cards with SFP's installed in them (http://www.startech.com/~PEX1000SFP) They have some extremely unusual behavior that I'm curious if anyone on the list has ever seen or could shed some light on. Sometimes after bringing the network card up the network driver will continuously flap like: r8169 0000:01:00.0 eth2: link down r8169 0000:01:00.0 eth2: link up r8169 0000:01:00.0 eth2: link down r8169 0000:01:00.0 eth2: link up The link is obviously not usable in that state. On occasion though, some combination of down/up'ing the interface will actually bring things into a stable state and everything works well. Interestingly, the hardware link light does not fluctuate while this happens. I've tried with the kernel-based r8169 driver, and the r8168 driver from the Realtek site, but both exhibit the same behavior. I do see a number of "similar" reports online regarding this issue, has anyone here seen anything like this before? Neither raising the module debug level to 16 and raising msglvl with ethool produced nothing interesting. Any suggestions on where to look for more debug (or a better list to ask, if this isn't the right place) would be much appreciated. Thanks! -Adam