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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89987C433FE for ; Thu, 7 Oct 2021 20:19:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6858E61139 for ; Thu, 7 Oct 2021 20:19:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234100AbhJGUV1 (ORCPT ); Thu, 7 Oct 2021 16:21:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233019AbhJGUVY (ORCPT ); Thu, 7 Oct 2021 16:21:24 -0400 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89F69C061570; Thu, 7 Oct 2021 13:19:30 -0700 (PDT) Received: by mail-pj1-x102d.google.com with SMTP id pi19-20020a17090b1e5300b0019fdd3557d3so6058280pjb.5; Thu, 07 Oct 2021 13:19:30 -0700 (PDT) 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=e/YpkKIE5V6t4jxfXyZfu6YNrRapkO8I3i7VrwNsmgo=; b=Ik7548FW1CsZktkuXqabNxc2k4f6WZy2M7/RvyEA7Ho2dAuBOPKlzY6kFCVnPUfQ57 cfDDxZRwMHu9ssq5EBvvWkQmA97bmtKjmWtcZZQ0lCmGjvAnOAKmc10+Z3UkLnqNGD4j 3XUIQiawHjPSrLN3VXCTU9V89Pbk7JJskHwuixar7cSGwyDtngBnxFTc6DxRD/sikP/c AM50aRoGWqID1XNLhVBIGsmhPgaX8SnZdqF772rvUTFiSMgAd+jbAkAksrxqdXDSk11Z ohlGbx/SHQIi3JsrR/BfItJDSKo1YZ/XFOxykE6B9Geb3en3T5XB2xrF4cxviU+VptSX 6EtA== 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=e/YpkKIE5V6t4jxfXyZfu6YNrRapkO8I3i7VrwNsmgo=; b=Iqd+rng7yT9k7u/nOCAamfYPX6xZlQrpeWaVYLCQjce67dtujq5wnTFn3IVZcPJdoh bvuspO+Cn+azqEvRShyi2c+3iLjrSnMtrIqG2sslkESKg+MmrY4Q983SO6DBMc2+paQ+ JnWpqSR53BmIVwWS8+l4wyOmWqJH18L7cXVlIMio55dwbXS+iCxdy/rkWhsX979fDGGq DrGbTP1uBr7xMfosUlCFs6JRcuvyMJNQlorESv/aMqBTZxXo+duTMzAo/0EWD0LOQFCp cGNPuUmkAwgXNIYiU1dgwIXAfgay2+f57wR3Jt5prh2PDtpQV8KesLopnKZ1r6sxrcRq xm6A== X-Gm-Message-State: AOAM53386bS5O/G6SlZACCAROofixJ6Qv9sPae0d3vctVqC8BrGvbv1D cXC1uqEbDlCHihnEQWtBk20= X-Google-Smtp-Source: ABdhPJwSwnWVUspzEs/GcA6pZDZOGLTgtpVtvAlJaqH5FZFCtbqMICuRXigTQvWSj9qeCqu0ronAwA== X-Received: by 2002:a17:90a:1f05:: with SMTP id u5mr7127131pja.193.1633637970033; Thu, 07 Oct 2021 13:19:30 -0700 (PDT) Received: from hoboy.vegasvil.org ([2601:645:c000:2163:e2d5:5eff:fea5:802f]) by smtp.gmail.com with ESMTPSA id k190sm177087pgc.11.2021.10.07.13.19.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Oct 2021 13:19:29 -0700 (PDT) Date: Thu, 7 Oct 2021 13:19:27 -0700 From: Richard Cochran To: Sebastien Laveze Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, yangbo.lu@nxp.com, yannick.vignon@oss.nxp.com, rui.sousa@oss.nxp.com Subject: Re: [PATCH net-next] ptp: add vclock timestamp conversion IOCTL Message-ID: <20211007201927.GA9326@hoboy.vegasvil.org> References: <20210927093250.202131-1-sebastien.laveze@oss.nxp.com> <20210927145916.GA9549@hoboy.vegasvil.org> <20210927202304.GC11172@hoboy.vegasvil.org> <98a91f5889b346f7a3b347bebb9aab56bddfd6dc.camel@oss.nxp.com> <20210928133100.GB28632@hoboy.vegasvil.org> <0941a4ea73c496ab68b24df929dcdef07637c2cd.camel@oss.nxp.com> <20210930143527.GA14158@hoboy.vegasvil.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Oct 07, 2021 at 03:31:43PM +0200, Sebastien Laveze wrote: > For example: > Let's take a worst case, the PHC is adjusted every 10 ms, vclock every > 1 sec with 1 ppm error. You can't justify adjusting the HW clock and the vclocks asynchronously with a single, isolated example. If two independent processes are both adjusting a clock concurrently, asynchronously, and at different control rates, the result will be chaos. It does not matter that it *might* work for some random setup of yours. The kernel has to function correctly in general, not just in some special circumstances. Thanks, Richard