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[2620:137:e000::1:20]) by mx.google.com with ESMTP id kf13-20020a17090776cd00b00992acf279afsi8253755ejc.928.2023.07.25.20.57.55; Tue, 25 Jul 2023 20:58:20 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=H157GANR; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229959AbjGZDjy (ORCPT + 99 others); Tue, 25 Jul 2023 23:39:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229535AbjGZDjw (ORCPT ); Tue, 25 Jul 2023 23:39:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 748E52695 for ; Tue, 25 Jul 2023 20:39:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 116FC611C5 for ; Wed, 26 Jul 2023 03:39:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B7EB0C433C7; Wed, 26 Jul 2023 03:39:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690342790; bh=/DXkxDc0cjY513B5QGcbSthekDMBSig0Uuz5USmRB9g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=H157GANRAtY9o9O/MLKKTTbuWpOwR4XmTVaem5NtxNwnkOrUiwqdx6pKbPVRZyxZp XsrhqhKIY1O74VUIwmGYMvKVAa7F/mum5SbnVjk+tZ2dUYbv4brqLThJ0UPAXGhjc4 nO1vw4bl4Iv66QnJ4u0WwqG0pd8FueE8M/yzw7B4zWsoHYI1fbR9LYzkXa78PgjWTJ DQVv4aw6MZVD7uzWaIvbUJ/K4ImsCSxC73xWyDRUOXIUKsX1rSQlztJloyiBGiOJ7k N/h7SBzK5mn5cwjYvmMEe9Da0xYHpv5gXt/zbrYdsZGYhFItjoUZKl2NSaVLZrTUkP pK1jE7jQdNRTQ== Date: Tue, 25 Jul 2023 20:39:48 -0700 From: Jakub Kicinski To: Richard Cochran 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: <20230725203948.4037fee7@kernel.org> In-Reply-To: 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-Transfer-Encoding: 7bit X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 Jul 2023 20:22:53 -0700 Richard Cochran 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? I see :)