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, 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 E5D73C33CAA for ; Mon, 20 Jan 2020 10:50:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BBFE4207E0 for ; Mon, 20 Jan 2020 10:50:32 +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="G2Unp/Kt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726942AbgATKua (ORCPT ); Mon, 20 Jan 2020 05:50:30 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:33164 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726417AbgATKu3 (ORCPT ); Mon, 20 Jan 2020 05:50:29 -0500 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=OCp9nsRDYcWQsrV3GjryqLOSAJxrAWhH+tupDptDjZo=; b=G2Unp/Kt5L8sqcRcZviY2SFcr YPso8Lk+HuRnFhCgRGPkqSajiuXbYlc/M+AW3gxjxO604q0mH71Suv+HduzqpTa+I4BavJ0yCV8fd K9YZSh99KUPq0ix7i2+FrIiEOGQUplA/be98njgBOFTPSXJ7o54X4vNNsisZ6ePdPDlNHEKTznFVq fqyUN7uFkkrXBcnBK5GwzKpvXA17gS+wT8hdp0WZWKQok8EDjyIk7YemEc+prQPVKKuE8/dklRCjY EcpumKNUKaMqnBBC1+IrtgZJxcNscvU+1z8szaDfPYhnvQaE+bUotpT0VoPkcMoXrNhbr7dgKS7hT vnAKfX2/g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:40826) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1itUdT-0005bt-Vi; Mon, 20 Jan 2020 10:50:24 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1itUdQ-0002mK-U8; Mon, 20 Jan 2020 10:50:20 +0000 Date: Mon, 20 Jan 2020 10:50:20 +0000 From: Russell King - ARM Linux admin To: Jose Abreu Cc: Andrew Lunn , "netdev@vger.kernel.org" , Joao Pinto , Florian Fainelli , Heiner Kallweit , "David S. Miller" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC net-next] net: phy: Add basic support for Synopsys XPCS using a PHY driver Message-ID: <20200120105020.GB25745@shell.armlinux.org.uk> References: <4953fc69a26bee930bccdeb612f1ce740a4294df.1578921062.git.Jose.Abreu@synopsys.com> <20200113133845.GD11788@lunn.ch> <20200113141817.GN25745@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Mon, Jan 20, 2020 at 10:31:17AM +0000, Jose Abreu wrote: > From: Russell King - ARM Linux admin > Date: Jan/13/2020, 14:18:17 (UTC+00:00) > > > I've recently suggested a patch to phylink to add a generic helper to > > read the state from a generic 802.3 clause 37 PCS, but I guess that > > won't be sufficient for an XPCS. However, it should give some clues > > if you're intending to use phylink. > > So, I think for my particular setup (that has no "real" PHY) we can have > something like this in SW PoV: > > stmmac -> xpcs -> SW-PHY / Fixed PHY > > - stmmac + xpcs state would be handled by phylink (MAC side) > - SW-PHY / Fixed PHY state would be handled by phylink (PHY side) > > This would need updates for Fixed PHY to support >1G speeds. You don't want to do that if you have 1G SFPs. Yes, you *can* do it and make it work, but you miss out completely on the fact that the link is supposed to be negotiated across the SFP link for 1G speeds, and then you're into the realms of having to provide users ways to edit the DT and reboot if the parameters at the link partner change. Please, avoid fixed-links with SFPs where possible, and let's implement things correctly. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up