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 DC115C433EF for ; Sun, 13 Mar 2022 04:04:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233508AbiCMEFZ (ORCPT ); Sat, 12 Mar 2022 23:05:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229796AbiCMEFY (ORCPT ); Sat, 12 Mar 2022 23:05:24 -0500 Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD5D28BF3A; Sat, 12 Mar 2022 20:04:16 -0800 (PST) Received: by mail-pj1-x1033.google.com with SMTP id bx5so11542742pjb.3; Sat, 12 Mar 2022 20:04:16 -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=uksUDscG18pH8EI9uIGKs4R4Dd0p9gKfak1RBaRXBys=; b=AHhiVJ3UBkF49PV21p3KrPS9TLHac4Wb9F+3IGlTDZiDKwNLoLSCK7ymCrBjA/FB8g ymqHVMjFIl9JYl7Iu1Ge3wb3XNw1xesgT+ryR1GjrpuDxeEHCCnl/042FiL+/OS2evHF H2V5167S7Y3CWJhqaFveCWGFGyVfHP0NcfRZJhxMby5oCauTRuR1WBhhdjKstiqu2YSn WPfwG36Ugd7IBxh6uLZbE5y06m7q3+bl68he0wEMpT387ke8irt00/kGEHuLMJjmB82o qUlZlOvCSgw0wcF4AOuTUkD5jDpebm8oh77B/OQEvPMro3s/wrqUTUbCNGnRB9EeSHsJ kuYg== 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=uksUDscG18pH8EI9uIGKs4R4Dd0p9gKfak1RBaRXBys=; b=c8WkZiLo0k3jBta5YwQVQJ1rhPBO+Bw0yC2xA/8jbBgpfYmYfZqrFF8JQp5BLXNv1a fOU1aeWRza6MGH+3qHby3+G5iVKZXv8A7t+GNhVbVCMtuXRl/MRjKVW4iSVqCBGPIM35 ZW4olnH2BPpD+u+K+Bp6J04bH6Sr5lwQv42MRs3VrOrU4OP6b1xPS4GlkoRJUOliAvk2 EjY/mQj1se9X4gcvJXtSSgheqn3YjY0m836/WTZF/oSR6NJv/Jw1klEi1kz3A9rqd+Oq SFezF/uibq69uQSFz24vxel6zxsLaMJtZfhGbf8x0D4CsLLzdjYpKcsPACq1wEdgowA3 5ncw== X-Gm-Message-State: AOAM530LgWfI2jgjbvMih3+gjVHZ1bbtVMyiyhi6gbhyg+/Da1GrN3yE xXlnhudAr9+dTTpnCb4/PRI= X-Google-Smtp-Source: ABdhPJwpTnJVzXK4pQicWpojH8vBxMFMcbQP0DV2GLcxezgDZ5yuqgt8CS65wXuElZO48wwKZGX+vg== X-Received: by 2002:a17:903:124a:b0:153:47d7:de49 with SMTP id u10-20020a170903124a00b0015347d7de49mr5921852plh.81.1647144256165; Sat, 12 Mar 2022 20:04:16 -0800 (PST) Received: from hoboy.vegasvil.org ([2601:640:8200:33:e2d5:5eff:fea5:802f]) by smtp.gmail.com with ESMTPSA id oo17-20020a17090b1c9100b001bf0ccc59c2sm18337904pjb.16.2022.03.12.20.04.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 12 Mar 2022 20:04:15 -0800 (PST) Date: Sat, 12 Mar 2022 20:04:12 -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: <20220313040412.GA30488@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: devicetree@vger.kernel.org On Sat, Mar 12, 2022 at 08:36:20PM +0100, Allan W. Nielsen wrote: > I did skim through the articles, and as you hinted he does find small > latency differences across different packets. (but as I understood, very > few PHYs was tested). There is also previous work cited in those articles. > But this is not really an argument for not having _default_ values > hard-coded in the driver (or DT, but lets forget about DT for now). You put them in the DTS. That means you expect them to need changes. DTS is the WRONG place for such things. If your numbers are perfect, then do the corrections in silicon/firmware. If the numbers aren't 100% perfect, then provide your customers with a test report providing the recommended numbers. Include a proper explanation of the test methodology and assumptions used in your analysis. Heck, you can even given them linuxptp config snippets (and other for other popular PTP stacks, Oregano, ixat, ptpd, etc) Don't hard code random, changing numbers into kernel drivers. Thanks, Richard