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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 8D6A7C433E1 for ; Wed, 3 Jun 2020 14:59:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DCB220738 for ; Wed, 3 Jun 2020 14:59:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="CFQxCtsd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726077AbgFCO7K (ORCPT ); Wed, 3 Jun 2020 10:59:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725954AbgFCO7J (ORCPT ); Wed, 3 Jun 2020 10:59:09 -0400 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:3201:214:fdff:fe10:1be6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE17EC08C5C0; Wed, 3 Jun 2020 07:59:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=MtuKNw2pgwAhO9cB5wELdMt4OQ9HRQi1RszYbDAANfo=; b=CFQxCtsdhBH+Gn+g/+1aQuw+w /1Q060iK8zSrMm0PISy8jCuZjeSbRuC3qWJ4sS5Btp1z+cJuqMx3+qJk40ZiPglHtdCNv0WBJpGP3 dA7F8U9Dj+q9zQ8vtBUOr5O830OZ1bp00XiX6nkvlb4n5AVSU9dcjbxdeDRoBcHNYXAdCobz9Yp5S 8EEqSieVbAl1zx8x3m1Wl4uNco7Tc4uG4SfPP/XCWlKqgwKA6qazc4/7UIAZV3shJeJSQDexgPfDM y0uD5nqYNFHlwIVQIaiAUnbO1SWQ2EAB3rdi/GNSpmGEwy4eHjihoTHt7uyun2pi4jCWVHDu6vZM0 +T92XR1XQ==; Received: from shell.armlinux.org.uk ([2002:4e20:1eda:1:5054:ff:fe00:4ec]:38388) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jgUr6-0005gy-0Q; Wed, 03 Jun 2020 15:59:00 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1jgUr2-0005TW-NB; Wed, 03 Jun 2020 15:58:56 +0100 Date: Wed, 3 Jun 2020 15:58:56 +0100 From: Russell King - ARM Linux admin To: Andrew Lunn Cc: Thomas Bogendoerfer , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] net: mvpp2: Enable autoneg bypass for 1000BaseX/2500BaseX ports Message-ID: <20200603145856.GA1551@shell.armlinux.org.uk> References: <20200528163335.8f730b5a3ddc8cd9beab367f@suse.de> <20200528144805.GW1551@shell.armlinux.org.uk> <20200528204312.df9089425162a22e89669cf1@suse.de> <20200528220420.GY1551@shell.armlinux.org.uk> <20200529130539.3fe944fed7228e2b061a1e46@suse.de> <20200529145928.GF869823@lunn.ch> <20200529175225.a3be1b4faaa0408e165435ad@suse.de> <20200529163340.GI869823@lunn.ch> <20200602225016.GX1551@shell.armlinux.org.uk> <20200603132147.GW869823@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200603132147.GW869823@lunn.ch> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Jun 03, 2020 at 03:21:47PM +0200, Andrew Lunn wrote: > On Tue, Jun 02, 2020 at 11:50:17PM +0100, Russell King - ARM Linux admin wrote: > > On Fri, May 29, 2020 at 06:33:40PM +0200, Andrew Lunn wrote: > > > Given the current code, you cannot. Now we understand the > > > requirements, we can come up with some ideas how to do this properly. > > > > Okay, I've been a little quiet because of sorting out the ARM tree > > for merging with Linus (now done) and I've been working on a solution > > to this problem. > > > > The good news is, I have an implementation in phylink to use the sync > > status reported from a PCS, and to appropriately enable sync status > > reporting. I'm quite nervous about having that enabled as a matter of > > routine as I've seen some Marvell hardware end up with interrupt storms > > from it - presumably due to noise pickup on the serdes lines being > > interpreted as an intermittently valid signal. > > Hi Russell > > I have seen similar with an SFP without link. I think squelch is > optional, so noise gets passed through, which is enough to get and > loose sync. > > I think we probably need to only enable the interrupt when the LOS > signal indicates there is at least some power coming into the SFP. This doesn't help in Thomas' case, there is no LOS signal. I was proposing that Thomas uses fixed-link to describe the setup (because that's exactly what it is) but use the serdes sync status as an additional gate for "link up". Given that we have platforms that hammer the CPU with interrupts when AN bypass is enabled, I think that setup is also a non-starter for the mainline kernel without some way for firmware to tell the kernel that it's okay to use it. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC for 0.8m (est. 1762m) line in suburbia: sync at 13.1Mbps down 424kbps up