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 14644C43331 for ; Fri, 27 Mar 2020 21:49:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C82DE206DB for ; Fri, 27 Mar 2020 21:49:02 +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="MhPwF2AU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727655AbgC0VtC (ORCPT ); Fri, 27 Mar 2020 17:49:02 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:40256 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727548AbgC0VtB (ORCPT ); Fri, 27 Mar 2020 17:49:01 -0400 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=6RKUwhhVvgfoGMJCpKlIDOvfeqhBKdoj/xwfI4aqz7w=; b=MhPwF2AU8VP5jr4prFyJWNn9v TOR+ZW938HT4E9QNuauhOeilPDN11TvsY0PMwGSq3ZZvLR0w9IdgHNFR4QU7POJRsv2Y6wNcv84e3 e14UPeUhoxTB5yDCJkacubXJ0bJpJK8JMAcO7EmS14KAT645U9N4xt3FfA/fvS52W3oExA0MEwxAD HW3WedzJyeBz2nLk+ArzCcUZzekNYCyqj+XSsd/HSgyd2dLJh6wS17v2BjrpRO7qu/7yciwY8zNN3 xYQCbz98tMhQfMt/LNV4ViUUyQG7Qi+nfBfmujgSHP2Ni/Jn18xsHm08VWgfbBsWu7sbDXcenUWOh dURqyiNMQ==; Received: from shell.armlinux.org.uk ([2002:4e20:1eda:1:5054:ff:fe00:4ec]:38076) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jHwqW-0003Tu-Mh; Fri, 27 Mar 2020 21:48:56 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1jHwqU-0004Zz-Gm; Fri, 27 Mar 2020 21:48:54 +0000 Date: Fri, 27 Mar 2020 21:48:54 +0000 From: Russell King - ARM Linux admin To: Andrew Lunn Cc: David Miller , netdev , Vivien Didelot Subject: Re: [PATCH net-next 2/2] net: dsa: mv88e6xxx: Set link down when changing speed Message-ID: <20200327214854.GS25745@shell.armlinux.org.uk> References: <20200323214900.14083-1-andrew@lunn.ch> <20200323214900.14083-3-andrew@lunn.ch> <20200323220113.GX25745@shell.armlinux.org.uk> <20200323223934.GA14512@lunn.ch> <20200327111316.GF25745@shell.armlinux.org.uk> <20200327212608.GU3819@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200327212608.GU3819@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 Fri, Mar 27, 2020 at 10:26:08PM +0100, Andrew Lunn wrote: > > > Hi Russell > > > > > > So the problem here is that CPU and DSA ports should default to up and > > > at their fastest speed. During setup, the driver is setting the CPU > > > port to 1G and up. Later on, phylink finds the fixed-link node in DT, > > > and then sets the port to 100Mbps as requested. > > > > > > How do you suggest fixing this? If we find a fixed-link, configure it > > > first down and then up? > > > > I think this is another example of DSA fighting phylink in terms of > > what's expected. > > > > The only suggestion I've come up so far with is to avoid calling > > mv88e6xxx_port_setup_mac() with forced-link-up in > > mv88e6xxx_setup_port() if we have phylink attached. > > Hi Russell > > Yes, that might work. But it is a solution specific to mv88e6xxx. I > guess other switches could have a similar issue. > > Is it really that bad to add the link down as i proposed? Do we even > have a guarantee the port is down before phylink starts configuring > it, for all switch drivers? That's partly why I made the suggestion, as mac_config() could end up being called with potential changes to the configuration with the link already up. If that can happen, then it's not just about the link being down before mac_link_up() is called... -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 10.2Mbps down 587kbps up