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=-3.8 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 0F544C433E0 for ; Mon, 18 Jan 2021 19:46:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CFA2622C9D for ; Mon, 18 Jan 2021 19:46:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437373AbhART2Q (ORCPT ); Mon, 18 Jan 2021 14:28:16 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:46606 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437318AbhART0z (ORCPT ); Mon, 18 Jan 2021 14:26:55 -0500 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1l1aAG-001Kh2-Gf; Mon, 18 Jan 2021 20:26:12 +0100 Date: Mon, 18 Jan 2021 20:26:12 +0100 From: Andrew Lunn To: Tobias Waldekranz Cc: Chris Healy , Marek Behun , netdev Subject: Re: bug: net: dsa: mv88e6xxx: serdes Unable to communicate on fiber with vf610-zii-dev-rev-c Message-ID: References: <20200718164239.40ded692@nic.cz> <20200718150514.GC1375379@lunn.ch> <20200718172244.59576938@nic.cz> <8735yykv88.fsf@waldekranz.com> <87zh16jfxd.fsf@waldekranz.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87zh16jfxd.fsf@waldekranz.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > >> I am seeing the exact same issue. I have tried both a 1000base-x SFP and > >> a copper 1000base-T and get the same result on both - transmit is fine > >> but rx only works up to the SERDES, no rx MAC counters are moving. > > > > Hi Tobias > > > > We never tracked this down. I spent many hours bashing my head against > > this. I could not bisect it, which did not help. > > Well that is disheartening :) "I could not bisect it", does that mean > that it did work at some point but your CPU platform was not supported > far enough back, or has it never worked? As far as i remember, Ports 9 and 10 did work once. I suspect it could of been early on, before we had much support for the SERDES, it relied on the strapping being correct, and the switch powering up in the right mode. We also do a dance with the cmode of ports 9 and 10, dropping them down to slower speeds making the SERDES available for the other ports and then changing the cmode again if the port is supposed to use a higher speed and needs multiple SERDESes. The board which had trouble and i was debugging on only has limited support, not going back too far. I would probably need to reproduce the issue on different hardware to have more scope for going backwards and trying to find a setup where ports 9 or 10 did work, as a basis for a bisect. Andrew