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 2982DC83000 for ; Wed, 29 Apr 2020 18:57:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1B13208E0 for ; Wed, 29 Apr 2020 18:57:33 +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="QSdyR1WX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727071AbgD2S5d (ORCPT ); Wed, 29 Apr 2020 14:57:33 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:60346 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726423AbgD2S5c (ORCPT ); Wed, 29 Apr 2020 14:57:32 -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=uS9qOnGXgNTdEq8TAB+IhEPZs/o7LS8aQIdvZ0PrftY=; b=QSdyR1WXD7yi7NPAOIrWIOPadt dV7CwHbJL2xXoAPpsjsaWWEJz3Vqz8koS4HhY59LBpmKSx8os+qRwoByAUR9To4jB/evn/TO6TrDp mdqYPLC/T25Uflu3TWL+GxnbRpx3Jgks1aBC1w9s0iTANBgaKKa/nZHyCJwG9YYqCjZM=; Received: from andrew by vps0.lunn.ch with local (Exim 4.93) (envelope-from ) id 1jTrtf-000JDW-9h; Wed, 29 Apr 2020 20:57:27 +0200 Date: Wed, 29 Apr 2020 20:57:27 +0200 From: Andrew Lunn To: Michael Walle Cc: cphealy@gmail.com, davem@davemloft.net, f.fainelli@gmail.com, hkallweit1@gmail.com, mkubecek@suse.cz, netdev@vger.kernel.org Subject: Re: [PATCH net-next v1 4/9] net: ethtool: Add attributes for cable test reports Message-ID: <20200429185727.GP30459@lunn.ch> References: <20200425180621.1140452-5-andrew@lunn.ch> <20200429161605.23104-1-michael@walle.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200429161605.23104-1-michael@walle.cc> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Apr 29, 2020 at 06:16:05PM +0200, Michael Walle wrote: > Hi, > > > > > > +enum { > > > > > + ETHTOOL_A_CABLE_PAIR_0, > > > > > + ETHTOOL_A_CABLE_PAIR_1, > > > > > + ETHTOOL_A_CABLE_PAIR_2, > > > > > + ETHTOOL_A_CABLE_PAIR_3, > > > > > +}; > > > > > > > > Do we really need this enum, couldn't we simply use a number (possibly > > > > with a sanity check of maximum value)? > > > > > > They are not strictly required. But it helps with consistence. Are the > > > pairs numbered 0, 1, 2, 3, or 1, 2, 3, 4? > > > > OK, I'm not strictly opposed to it, it just felt a bit weird. > > Speaking of the pairs. What is PAIR_0 and what is PAIR_3? Maybe > it is specified somewhere in a standard, but IMHO an example for > a normal TP cable would help to prevent wild growth amongst the > PHY drivers and would help to provide consistent reporting towards > the user space. Hi Michael Good question Section 25.4.3 gives the pin out for 100BaseT. There is no pair numbering, just transmit+, transmit- and receive+, receive- signals. 1000BaseT calls the signals BI_DA+, BI_DA-, BI_DB+, BI_DB-, BI_DC+, BI_DC-, BI_DDA+, BI_DD-. Comparing the pinout 100BaseT would use BI_DA+, BI_DA-, BI_DB+, BI_DB. But 1000BaseT does not really have transmit and receive pairs due to Auto MDI-X. BroadReach calls the one pair it has BI_DA+/BI_DA-. Maybe it would be better to have: enum { ETHTOOL_A_CABLE_PAIR_A, ETHTOOL_A_CABLE_PAIR_B, ETHTOOL_A_CABLE_PAIR_C, ETHTOOL_A_CABLE_PAIR_D, }; Andrew