From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264022AbUEMKcR (ORCPT ); Thu, 13 May 2004 06:32:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264061AbUEMKcQ (ORCPT ); Thu, 13 May 2004 06:32:16 -0400 Received: from usergc137.dsl.pipex.com ([62.190.170.137]:779 "EHLO gateway.office.e-tv-interactive.com") by vger.kernel.org with ESMTP id S264022AbUEMKcM (ORCPT ); Thu, 13 May 2004 06:32:12 -0400 Subject: Natsemi ethernet 'cable magic' fix can cause problems From: Colin Paton To: linux-kernel@vger.kernel.org Content-Type: text/plain Organization: eTV Interactive Ltd Message-Id: <1084444503.4548.141.camel@colinp> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 (1.4.5-7) Date: Thu, 13 May 2004 11:35:03 +0100 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, This information may be useful to anyone who uses the natsemi ethernet driver. I have discovered that the 'do_cable_magic()' call introduced into the driver in kernels 2.4.20 and later can cause problems. Some machines we have use the Natsemi DP83815 chip, which worked with no problems using kernel 2.4.19. Following an upgrade to 2.4.25 a few of the boxes stopped working - but most were still OK. The problem was strange - about 30% packet loss was experienced during pings. Moving the box to a different ethernet wall outlet (but still using the same port on the switch) cured the problem. The problem therefore appeared to be cable dependant. It would appear that the call to 'do_cable_magic()' in drivers/net/natsemi.c causes the problem to occur. It looks as though this was added in to actually *fix* such problems... but in our case it made things worse. The cable problems were never experienced before, and everything seems fine now that this call has been removed. I'm not sure of the correct way to fix this problem, but I'm hoping that this information might be useful to others who encounter something similar. Colin