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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 6F0BBC433E0 for ; Wed, 27 May 2020 20:52:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 446432088E for ; Wed, 27 May 2020 20:52:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="WyvaIFrA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728742AbgE0Uwm (ORCPT ); Wed, 27 May 2020 16:52:42 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:53104 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726129AbgE0Uwm (ORCPT ); Wed, 27 May 2020 16:52:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender: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=gKAXQgUdWQP/zL1P3eNew3G65B4gJ6Xt1zF4bmT1hDg=; b=WyvaIFrAsWiNdYbeeSXajmyKD6 6I8uuI6yBuqgB3E3YJb/fM/ogGpVN6EhTp9s1KROW2q6RwLo9hFHGFaGz8E86tphPbfvG8p5+xnMf sGW6H/UMHw8y6QxnMjTQRLU/Qwgf3L6OJ4PFdtaTMogDnXyqRrvzHFcIlrmKLtm3N/6c=; Received: from andrew by vps0.lunn.ch with local (Exim 4.93) (envelope-from ) id 1je32D-003S61-VH; Wed, 27 May 2020 22:52:21 +0200 Date: Wed, 27 May 2020 22:52:21 +0200 From: Andrew Lunn To: Geert Uytterhoeven Cc: Oleksij Rempel , Philippe Schenker , "sergei.shtylyov@cogentembedded.com" , "kernel@pengutronix.de" , "davem@davemloft.net" , "hkallweit1@gmail.com" , "linux@armlinux.org.uk" , "linux-kernel@vger.kernel.org" , "david@protonic.nl" , "netdev@vger.kernel.org" , "f.fainelli@gmail.com" , "linux-renesas-soc@vger.kernel.org" , Kazuya Mizuguchi , Grygorii Strashko Subject: Re: [PATCH net-next v3] net: phy: micrel: add phy-mode support for the KSZ9031 PHY Message-ID: <20200527205221.GA818296@lunn.ch> References: <20200422072137.8517-1-o.rempel@pengutronix.de> <20200428154718.GA24923@lunn.ch> <6791722391359fce92b39e3a21eef89495ccf156.camel@toradex.com> <20200429092616.7ug4kdgdltxowkcs@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > You may wonder what's the difference between 3 and 4? It's not just the > PHY driver that looks at phy-mode! > drivers/net/ethernet/renesas/ravb_main.c:ravb_set_delay_mode() also > does, and configures an additional TX clock delay of 1.8 ns if TXID is > enabled. Hi Geert That sounds like a MAC bug. Either the MAC insert the delay, or the PHY does. If the MAC decides it is going to insert the delay, it should be masking what it passes to phylib so that the PHY does not add a second delay. This whole area of RGMII delays has a number of historical bugs, which often counter act each other. So you fix one, and it break somewhere else. In this case, not allowing skews for plain RGMII is probably being too strict. We probably should relax that constrain in this case, for this PHY driver. Andrew