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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16E95C433EF for ; Sun, 13 Mar 2022 02:41:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233433AbiCMCm6 (ORCPT ); Sat, 12 Mar 2022 21:42:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233385AbiCMCm5 (ORCPT ); Sat, 12 Mar 2022 21:42:57 -0500 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD5218E187; Sat, 12 Mar 2022 18:41:50 -0800 (PST) Received: by mail-pl1-x62d.google.com with SMTP id n15so10864811plh.2; Sat, 12 Mar 2022 18:41:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=1fskSP0gHERAtz5LalHkiwzylQjQwe89pEx6fQtp0KU=; b=nuaDnykYqpqHHDXkEJjdRwt3rvLdCah9IO+tYgdEVvzbW7oreof2LjyZAYQEEyS37p 2eiRXF03z+Iu632ooK6v/yptBJLSqWseKc3g4Ok1qmdGW8N6yVaK7rdM/726SckB3OQ4 8N8E3Xtob+3I9VyVhp+dKXrsq+ERf3YgKP+FbiBBvQAg0pqRc818l+UzTyn6222/q4Yu vA57n/tX6gmbV2D0OHdAa2zSyrSDFdQSZOPQI3J1XNgAQ0l6lPr8scqVUJ0AlzWYYaPq DjTz/4c478lJp2zM/TO83/b+SXwwD/PB87gnciq/a2Q/5FmvxkQi0XIP49ZAOWmDdpTe P0Aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=1fskSP0gHERAtz5LalHkiwzylQjQwe89pEx6fQtp0KU=; b=LDwvY5KPgOFolH+AoD0zqmuJcXLAtGhwxTdyQqiCeQeenlTfDydCjDdI56rt7t7n8z OuWK8+g83nGQ8QcxqDxviMURN/BpD/UVn0dg2J7jPMcN3y+Qfep3Mu7pF4nbDDVd7afD b2gj8THFWF2FKpoFGclKht7GdqPHN+V5e7OLmvKr4e+hmdenq6zz/dkqJmN4b1Ac3aFw 99f5Jk1WgA6M0AmgkW1UgVT82ori09P0LytZUGeZMGCoxLu/83J8dUgOyUEHaVQlQp53 SbU4SwKAxSoFHYOIn/WJ/PSX+NOHqwAAUqVwthTJYiNpZMmBSMwvMMX7nsxy5B7saNcx NoQA== X-Gm-Message-State: AOAM531V99mbPYcvkeNI4a1AFU3BsgoxjNKAXigp7SJr0FXgvugSaYwp 5Y21Q7xL2CiJSsGFl5nI3gE= X-Google-Smtp-Source: ABdhPJwVsLdRl9naAj33/DxeBv99mrEP2FURQlajcdcPPUBf2U9/Q3Vci+rEmwqkSh5FzOBIrRxlsA== X-Received: by 2002:a17:902:6902:b0:14d:6aa4:f3f5 with SMTP id j2-20020a170902690200b0014d6aa4f3f5mr18008224plk.20.1647139310204; Sat, 12 Mar 2022 18:41:50 -0800 (PST) Received: from hoboy.vegasvil.org ([2601:640:8200:33:e2d5:5eff:fea5:802f]) by smtp.gmail.com with ESMTPSA id x6-20020a17090aa38600b001bce781ce03sm12825798pjp.18.2022.03.12.18.41.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 12 Mar 2022 18:41:49 -0800 (PST) Date: Sat, 12 Mar 2022 18:41:46 -0800 From: Richard Cochran To: "Allan W. Nielsen" Cc: Horatiu Vultur , "Russell King (Oracle)" , Andrew Lunn , Divya.Koppera@microchip.com, netdev@vger.kernel.org, hkallweit1@gmail.com, davem@davemloft.net, kuba@kernel.org, robh+dt@kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, UNGLinuxDriver@microchip.com, Madhuri.Sripada@microchip.com, Manohar.Puri@microchip.com Subject: Re: [PATCH net-next 2/3] dt-bindings: net: micrel: Configure latency values and timestamping check for LAN8814 phy Message-ID: <20220313024146.GB29538@hoboy.vegasvil.org> References: <20220308154345.l4mk2oab4u5ydn5r@soft-dev3-1.localhost> <20220308221404.bwhujvsdp253t4g3@soft-dev3-1.localhost> <20220309132443.axyzcsc5kyb26su4@soft-dev3-1.localhost> <20220309195252.GB9663@hoboy.vegasvil.org> <20220311142814.z3h5nystnrkvbzek@soft-dev3-1.localhost> <20220311150842.GC7817@hoboy.vegasvil.org> <20220312193620.owhfd43dzzxtytgs@den-dk-m31684h> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220312193620.owhfd43dzzxtytgs@den-dk-m31684h> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sat, Mar 12, 2022 at 08:36:20PM +0100, Allan W. Nielsen wrote: > With this in mind, I do agree with you that it does not make much sense > to compensate they few cm of PCB tracks without also calibrating for > differences from packet to packet. The PCB traces AFTER the PHY are part of the network, and if they contribute to path asymmetry, then that can and should be corrected using the delayAsymmetry configuration variable. > If we do not offer default delays directly in the driver, everybody will > have to calibrate all boards just to have decent results, we will not > have a good way to provide default delay numbers, and this will be > different from what is done in other drivers. Who says the other drivers are even remotely reasonable? Not me. I've been fighting this voodoo engineering all along, but people seem to ignore me. > I do understand that you have a concern that these numbers may change in > future updates. But this has not been a problem in other drivers doing > the same. Wrong. See the git history of the i210 driver. Also the data sheets. > But if this is still a concern, we can add a comment to say > that these numbers must be treated as UAPI, and chancing them, may > cause regressions on calibrated PHYs. Comments will be ignored. And when the next batch of developers comes along, they will ignore your prohibition. Thanks, Richard