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 BCFA8C43331 for ; Fri, 27 Mar 2020 17:35:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90D2B2073B for ; Fri, 27 Mar 2020 17:35:23 +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="jzfSJFSj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727699AbgC0RfW (ORCPT ); Fri, 27 Mar 2020 13:35:22 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:37382 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726738AbgC0RfW (ORCPT ); Fri, 27 Mar 2020 13:35:22 -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=ZBw9o6watwDnhvDMeAgnKRN69VRM8VBKTDHTKhljwTs=; b=jzfSJFSjQAp7L+DZ2FFYtMgQe y1mQA5paQGlunQ9gxYvq1icU474mu8+UQbPOEgHsPmTXw/BK7lO1pVuggeqq7KxgrYypZnRAQ+aLi yn4YzLA4cwVqKErTn0T5C4KsZ33WFGEQYyU+nLBH/S+rld8vvdLnI8GKtPg307FTcaIkMbbYX0R32 5FGWPOL6OdpMlZ5FhK4Xke/x6/6f8CRxw0uu800ZD6wezkPSRfTnstb83e7+lmMxAltI+fKcJCUo5 mfI98bk/JKfWSF81tWjFCbXYU6WJXQLF5Wu39TwqQa3KIFtq9hRivDbowGYHeGNBVHu/MMiNcTZrW LqLG9c56w==; Received: from shell.armlinux.org.uk ([2001:4d48:ad52:3201:5054:ff:fe00:4ec]:58714) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jHssx-0002Oj-Cz; Fri, 27 Mar 2020 17:35:11 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1jHsst-0004P3-7e; Fri, 27 Mar 2020 17:35:07 +0000 Date: Fri, 27 Mar 2020 17:35:07 +0000 From: Russell King - ARM Linux admin To: Andrew Lunn Cc: Florinel Iordache , "davem@davemloft.net" , "netdev@vger.kernel.org" , "f.fainelli@gmail.com" , "hkallweit1@gmail.com" , "devicetree@vger.kernel.org" , "linux-doc@vger.kernel.org" , "robh+dt@kernel.org" , "mark.rutland@arm.com" , "kuba@kernel.org" , "corbet@lwn.net" , "shawnguo@kernel.org" , Leo Li , "Madalin Bucur (OSS)" , Ioana Ciornei , "linux-kernel@vger.kernel.org" Subject: Re: [EXT] Re: [PATCH net-next 2/9] dt-bindings: net: add backplane dt bindings Message-ID: <20200327173507.GQ25745@shell.armlinux.org.uk> References: <1585230682-24417-1-git-send-email-florinel.iordache@nxp.com> <1585230682-24417-3-git-send-email-florinel.iordache@nxp.com> <20200327010411.GM3819@lunn.ch> <20200327152849.GP25745@shell.armlinux.org.uk> <20200327154448.GK11004@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200327154448.GK11004@lunn.ch> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 27, 2020 at 04:44:48PM +0100, Andrew Lunn wrote: > > What worries me is the situation which I've been working on, where > > we want access to the PCS PHYs, and we can't have the PCS PHYs > > represented as a phylib PHY because we may have a copper PHY behind > > the PCS PHY, and we want to be talking to the copper PHY in the > > first instance (the PCS PHY effectivel ybecomes a slave to the > > copper PHY.) > > I guess we need to clarify what KR actually means. If we have a > backplane with a MAC on each end, i think modelling it as a PHY could > work. > > If however, we have a MAC connected to a backplane, and on the end of > the backplane is a traditional PHY, or an SFP cage, we have problems. > As your point out, we cannot have two PHYs in a chain for one MAC. > > But i agree with Russell. We need a general solution of how we deal > with PCSs. What really worries me is that we may be driving the same hardware with two different approaches/drivers for two different applications which isn't going to work out very well in the long run. -- 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