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 BEF8FEB64DD for ; Wed, 26 Jul 2023 03:23:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230438AbjGZDXE (ORCPT ); Tue, 25 Jul 2023 23:23:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230285AbjGZDW6 (ORCPT ); Tue, 25 Jul 2023 23:22:58 -0400 Received: from mail-io1-xd34.google.com (mail-io1-xd34.google.com [IPv6:2607:f8b0:4864:20::d34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D57F2682; Tue, 25 Jul 2023 20:22:57 -0700 (PDT) Received: by mail-io1-xd34.google.com with SMTP id ca18e2360f4ac-78706966220so53146439f.1; Tue, 25 Jul 2023 20:22:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690341777; x=1690946577; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=NL3EuYyvjjhZCYD78dzuWYzAA4q7ImU5255kcivdAlA=; b=YrDQVT3n1O3EiYwvIGJo9jid1fKsLNw2s5BtVJ5JvGxYyPR1XjrUtnjfk86ybuDqvD mjkbbUuyR5VaB9rjSCR72ECLkPoHrMLk2ceMPKchY63bLMTQ0uCFoaZDI1rHSRdcZkBa Rj4LJYewPahFgAw+IE0I66Qm8T3wULByAcoETQYDq8VJzatnTf4P27YEUdI0SknFz3lz XEQP6TM/KY0h1JyYR68C89+l8h3L8U59mSzM8/oIOIzhC7QsCaK/HqQy8I1TjSgmiW8m rYeskGDA9hosrrCFYfjvbKnf/0CWiTVMAuWvQE8UyAnzJLx1bvG10rIKl4kTIK4KL4+E i4Jg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690341777; x=1690946577; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=NL3EuYyvjjhZCYD78dzuWYzAA4q7ImU5255kcivdAlA=; b=ZFUKr3MXFFgpLVQJoQ99KRY+WH6Go2sZFT0h+jdGANo7rzlk8tpjzBo7G7WJZSCHeT 3tCbY6k1XVuoHm+FZ+4gEUGEazWKBca+5jWHT4N+OnF5NWYQRZFMAr6XvZi+T9MC54wd hIr1mM0BCvMECsNtC32s5ynjunHwcailj2ICnzTf5uh/K4bRHCvR14jVw3JUT2A/IsYs JJikH7aGPBifoJoDg49RUXogLq46FPxLxDCp2lzBcLTbxH6qlsQ47xyLsJLkjGYl7OJ2 c07ph9qLIp6zawMxw24yrwPK8M3WdjbwGqFibLr+TCIVeQ1QSpzhAMRwA5L7KIJZTCT0 /czA== X-Gm-Message-State: ABy/qLYY8J6bLZsCBf0b8xLtBhZUMlfv9hX6QAw0B3FEZf+AAfyN1mB3 Ym33E5S9SflmCttw05qfhmQ= X-Google-Smtp-Source: APBJJlH6yBw+cvBcbmXyvs1PZzwvZEc6/RU38mhLvcrD3wYRbKLXGce0SxktHOdc8rnQsf8pyEfhoA== X-Received: by 2002:a6b:1446:0:b0:77a:ee79:652 with SMTP id 67-20020a6b1446000000b0077aee790652mr603947iou.1.1690341776913; Tue, 25 Jul 2023 20:22:56 -0700 (PDT) Received: from hoboy.vegasvil.org ([2601:640:8000:54:e2d5:5eff:fea5:802f]) by smtp.gmail.com with ESMTPSA id i75-20020a639d4e000000b0055387ffef10sm134985pgd.24.2023.07.25.20.22.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Jul 2023 20:22:56 -0700 (PDT) Date: Tue, 25 Jul 2023 20:22:53 -0700 From: Richard Cochran To: Jakub Kicinski Cc: Johannes Zink , Giuseppe Cavallaro , Alexandre Torgue , Jose Abreu , "David S. Miller" , Eric Dumazet , Paolo Abeni , Maxime Coquelin , Russell King , patchwork-jzi@pengutronix.de, netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, kernel test robot Subject: Re: [PATCH v2] net: stmmac: correct MAC propagation delay Message-ID: References: <20230719-stmmac_correct_mac_delay-v2-1-3366f38ee9a6@pengutronix.de> <20230725200606.5264b59c@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230725200606.5264b59c@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 25, 2023 at 08:06:06PM -0700, Jakub Kicinski wrote: > any opinion on this one? Yeah, I saw it, but I can't get excited about drivers trying to correct delays. I don't think this can be done automatically in a reliable way, and so I expect that the few end users who are really getting into the microseconds and nanoseconds will calibrate their systems end to end, maybe even patching out this driver nonsense in their kernels. Having said that, I won't stand in the way of such driver stuff. After all, who cares about a few microseconds time error one way or the other? Thanks, Richard