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 27622C433EF for ; Sat, 12 Mar 2022 02:48:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230132AbiCLCtk (ORCPT ); Fri, 11 Mar 2022 21:49:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229505AbiCLCtg (ORCPT ); Fri, 11 Mar 2022 21:49:36 -0500 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7DE65132942; Fri, 11 Mar 2022 18:48:32 -0800 (PST) Received: by mail-pl1-x632.google.com with SMTP id q13so9121553plk.12; Fri, 11 Mar 2022 18:48:32 -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:content-transfer-encoding:in-reply-to :user-agent; bh=/QbyG5b+gu58LmSy08Yok7CVH6tbIv8OI8nBcPnh//o=; b=VGCvYKe86Qmt0bozZS/+t8wm2hRX+gn0qMv82VM4J+ZgD3yDNbZj/cvmraaFVLXz44 ST1xhsD5eUCTrFc/seeYdpC1nyr0r2oc9efFLe4As1YPesDY+oNshx9IRMsZWmhedv5f roUovRnrMBrWrNKA0OBIQ2YDOETa8qCAOlJzYqgt2A6mW1fMiiOIvvsx7T0hqoGpWm6y cgRRSU3Ct0qvbULzQhTKHjBQmzyBDp7ipdjYh8I2/JZd6R4fsaLYcD+mkoQjAaaa0wz2 1qZ9byifv3byyNRkLuPcyJ8Vzv9dOHn/NHvBFS8SOeuib0wQnIBDiEC9iWFtHMKq3Sda askg== 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:content-transfer-encoding :in-reply-to:user-agent; bh=/QbyG5b+gu58LmSy08Yok7CVH6tbIv8OI8nBcPnh//o=; b=6Fxhetzk3NpsX9UlDr6p63rYH7ldSpbQtXB58/ERr1lWKDwGomxb/nnmSpCM8L2Vsj 01IZdRHVcF9QogfFG3U41FIFTzbn61XCGEXsh8C1D/R4E/WDkqvplQTX+yMD4NFEu6U1 RysDq96gUnzVoxZmVf6pKnw6MzOIspARdaHShzExFMw5wP3lkrsqmXlh54+nqImlzUIi ANorpyl68q29pG9WH0iL0sTxhpYHJUmyuRNlUVaNFXgDW8QfX+6i/rK3FLPGp3DRnIzl 21r1+gEBmV2TgjFb780X2GPIEthYVx/4QfbW/wI+M5GjQZ/F0BEszhOCQxWvVBdbbDWJ VFcg== X-Gm-Message-State: AOAM533cJ+blCBTkBLdT5Z9c4KqSi5WoZjLKn0ocnmzSx9S6uum4rBYK /wmf6XBmVxa2hx9Tq8zIag4= X-Google-Smtp-Source: ABdhPJz3J7O/rNgX0CpFlkzK7uDxO5Fx+Y+H+FeHN0n/8IZsGArnxxnU2d7UsdpojmXRt/YWwQ9p0A== X-Received: by 2002:a17:90a:8591:b0:1b9:da10:2127 with SMTP id m17-20020a17090a859100b001b9da102127mr25128598pjn.13.1647053311967; Fri, 11 Mar 2022 18:48:31 -0800 (PST) Received: from hoboy.vegasvil.org ([2601:640:8200:33:e2d5:5eff:fea5:802f]) by smtp.gmail.com with ESMTPSA id x18-20020a63b212000000b003807411b89esm9685936pge.54.2022.03.11.18.48.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Mar 2022 18:48:31 -0800 (PST) Date: Fri, 11 Mar 2022 18:48:28 -0800 From: Richard Cochran To: Woojung.Huh@microchip.com Cc: linux@armlinux.org.uk, Horatiu.Vultur@microchip.com, andrew@lunn.ch, 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: <20220312024828.GA15046@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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 11, 2022 at 03:21:58PM +0000, Woojung.Huh@microchip.com wrote: > If you are referring to the delayAsymmetry of ptp4l, No, really, I'm not. PTP4l(8) System Manager's Manual PTP4l(8) NAME ptp4l - PTP Boundary/Ordinary/Transparent Clock ... egressLatency Specifies the difference in nanoseconds between the actual transmission time at the reference plane and the reported trans‐ mit time stamp. This value will be added to egress time stamps obtained from the hardware. The default is 0. ingressLatency Specifies the difference in nanoseconds between the reported re‐ ceive time stamp and the actual reception time at reference plane. This value will be subtracted from ingress time stamps obtained from the hardware. The default is 0. > So, this latency should (hopefully) be not-much-change in the same board after manufactured. Please read the papers on this topic. I posted links in another reply in this thread. > Of cause, all values may be small enough to ignore though. > Do I miss something here? Yes, you miss the point entirely. PHY delays are relatively large and cannot be even measured in some cases. However, for well behaved PHYs, the user space stack already covers the configuration. Thanks, Richard