From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 909FCC433E5 for ; Sat, 18 Jul 2020 15:05:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 74DD02067D for ; Sat, 18 Jul 2020 15:05:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727867AbgGRPFR (ORCPT ); Sat, 18 Jul 2020 11:05:17 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:42694 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726155AbgGRPFR (ORCPT ); Sat, 18 Jul 2020 11:05:17 -0400 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1jwoOo-005m4F-Gv; Sat, 18 Jul 2020 17:05:14 +0200 Date: Sat, 18 Jul 2020 17:05:14 +0200 From: Andrew Lunn To: Chris Healy Cc: Marek Behun , netdev Subject: Re: bug: net: dsa: mv88e6xxx: serdes Unable to communicate on fiber with vf610-zii-dev-rev-c Message-ID: <20200718150514.GC1375379@lunn.ch> References: <20200718164239.40ded692@nic.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sat, Jul 18, 2020 at 07:49:26AM -0700, Chris Healy wrote: > On Sat, Jul 18, 2020 at 7:42 AM Marek Behun wrote: > > > > Hmm, nothing sticks out in the register dump. > > > > I encountered a similar problem 2 years ago on Topaz SERDES port when > > the cmode was set to 2500BASE-X but the speed register was set to speed > > incompatible with 2500BASE-X (I don't remember what, though). This > > issue was solved by a patch I sent to netdev. > > > > Are you sure that your board isn't broken? Maybe the SerDes traces on > > RX path are damaged... > > In my case, both the SERDES and the MAC are inside the switch so I > don't think it's likely that the SERDES traces are broken in there. > If you are referring to the traces between the SERDES and the fiber > module, that doesn't feel likely either as the SERDES appears to be > reporting successfully received frames: > > >From "ethtool -S" after sending 6 packets to the unit: > serdes_rx_pkts: 6 > serdes_rx_bytes: 384 > serdes_rx_pkts_error: 0 > > If the traces were broken between the fiber module and the SERDES, I > should not see these counters incrementing. Plus it is reproducible on multiple boards, of different designs. This is somehow specific to the 6390X ports 9 and 10. Andrew