From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm2-f13.google.com (mail-wm2-f13.google.com [74.125.225.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7E4534FECE6 for ; Tue, 29 Sep 2026 17:15:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.225.141 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790702137; cv=none; b=FHRqmGQs+Yr8rgUaSXPWvtNO9rCHGcXXxxXGnyQw4CTF90JNsMRy9ZIREb2X0mK0sur446Lvnejn9dp2hAPe0dTpE3UCcFnrCgI2DUX+1N0nhU2ZJsMbOiNZx4tlzPdCljXJBQPY01QqfmSWEo05RlvR6mYeYZbHblUflv3oij0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790702137; c=relaxed/simple; bh=zIe0KG3lCKETMKNwyZ7USTtDkAG4C6Fy+0s+JFPdz80=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=jnHVu6nj3KYeobDSO5FuHO7kSd4ObwAQP5nhBB6HegWSPmH/YdD4+ZYy2axBWq8UhQUWM3yf/imN9pHLWJqbVJ7G8BguDDaQYRmzDrCUVEsU/bDbRkQL3mQl77A1xREh2lIGZTMkPmbaoBmgSE9zx62Pn0yfX4u7f4Sy+RzbHes= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com; spf=pass smtp.mailfrom=baylibre.com; dkim=pass (2048-bit key) header.d=baylibre.com header.i=@baylibre.com header.b=DBvONZab; arc=none smtp.client-ip=74.125.225.141 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=baylibre.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=baylibre.com header.i=@baylibre.com header.b="DBvONZab" Received: by mail-wm2-f13.google.com with SMTP id 5b1f17b1804b1-49e71cdb22bso33316565e9.2 for ; Tue, 29 Sep 2026 10:15:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre.com; s=google; t=1790702134; x=1791306934; darn=vger.kernel.org; h=content-type:mime-version:message-id:date:references:in-reply-to :subject:cc:to:from:from:to:cc:subject:date:message-id:reply-to :content-type; bh=gliMXdJJkSbMhSXEgRAl5Ekvovgp6Cfw/QE4Z+KNG5E=; b=DBvONZabvKnsYyZDaFRrdDX4ywN2QKh0WQdGkCg4VuZAb8tWIBBXVgo69ctSNkC6iG R8Mb/fU3w1uQTatU4IMBRVI58LNV5eayLGJcEwEssU03d5eazY6TfsRi87hEhjgVXEgS KGD7qVj17lj4yPJwHCnA/zASIMl6qORzMoEMbWmaP3GWmyx4X9lVqBU2i8/GqD2MLR4v GjQQ2Qj3/SYPifWUoPyuGIefuLsSIQMeo8SxIHZOu6yIH4DapD4w2TzWbabU/ELl+A7f HZ+tH32EGR30KD/IGk6m25cjweaD5rmx+vUarLvuhpVA1EfjVSkVI09zvU2Olba2CmG2 CgXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790702134; x=1791306934; h=content-type:mime-version:message-id:date:references:in-reply-to :subject:cc:to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to:content-type; bh=gliMXdJJkSbMhSXEgRAl5Ekvovgp6Cfw/QE4Z+KNG5E=; b=xMTGpG+Rs9YtqyRwioKH0Kim6PDwfDnpHc2Ieh8FrSizz6chnQ3xJZuvt3dtIhjUtA UoomdRBjWJKHuuYPr2xr8wfMHYBC/gl2jsoEy5IAavHWSsg8lZmp6CDJouYG7NvCh7ms jJo3qN6gLUq88TK2NBAeKXKP+W9wPi55FBRAZJJcItf0xOTkpXalxWSbr2mWw2K7jOEa YVHCx4NymtS8Wejd9++hqqZki7rYzgrMr6Nau1wirSbVDBYnkSzxH6XOwPmDmt5Zqn5J l4QUHPw2K+N0+ODaEpoNyfBq4Y/j6c9//YVAR90tEmKBmzIBepxpZA2TZO9msLSDaF5D Du0A== X-Forwarded-Encrypted: i=1; AKwUvBzMUHvbhM/fUlM7fUNlivGo51vtc3Y6WKmV3+qqjzPIipgcrFMsNltI6gVvFQdSfCMrWD7CuAJYIexu@vger.kernel.org X-Gm-Message-State: AFuF++meSIQFAOKcAbt9eMNF9oGknWeBfYBlUNmN6bd4oDlmj8fR2A40 ZOc5n2rzFdIAmRzVyhOBAMTgJ9SQgnJLM6mvxKPNBrgFn4754Q6NTaeoDh/ugb5aB64= X-Gm-Gg: AYBFou3N1lN5EDhL2ntNYNhuqiW74WKwGaYYFuhGwpFuqkaNj4I4WQWhh6MLGk0ndIZ V/Viyt5RZbwrSmoeKokGmlLB3pOHPzIqUrn36fttBXlhsSWVj9bCrlELknSSaR552uaCuyfWplm mo+sNkVSyZ8MTZ6iBqnNdMO7VYvzJjtRrH8xB3A0h2zF/5tgrX6FtPXkZ4pvt9OTkiAssuMZ3O8 lxJsC/Phsw1Cvd6TcT5aN07FO3WpnVnSKxI8TDnMuL56fDFt5Pu7QPjCUF4zZi1gcLuLhCsFCM2 0yw+l0XGeEL4lNX2xDvAuV+s/HPUpJX/gv2ZjfXVO4Qt5CxSuX1WuQ91ptR4hZCOyYanUREheqx ls/cdnyireJoYfaNiiLm8YymOn+viEpVRuVF3KLQUrxY6k/4Z1jKZ85jCzvEWaqccLtA9w9Nj6e gjtB3n5P9BdMM4scC3uDx3NOAYw30GWt1lzQwjIuuGlh4Bgx/88T6xQ2IV+uROWpIOM3hoP6drq N+eooGi//8CpP0GUQ== X-Received: by 2002:a05:600c:530f:b0:49f:ffdc:939d with SMTP id 5b1f17b1804b1-49fffdc9a4amr125086635e9.9.1790702133757; Tue, 29 Sep 2026 10:15:33 -0700 (PDT) Received: from localhost (82-67-6-57.subs.proxad.net. [82.67.6.57]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4a00cfae123sm101113665e9.13.2026.09.29.10.15.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Sep 2026 10:15:33 -0700 (PDT) From: Jerome Brunet To: Andrew Lunn Cc: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Richard Cochran , Maxime Ripard , Maxime Coquelin , Alexandre Torgue , Philipp Zabel , Maxime Chevallier , netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, Andre Przywara Subject: Re: [PATCH net-next v3 0/5] net: stmmac: Add support for Allwinner A733 GMAC210 In-Reply-To: <93870bce-b18e-4eed-a9ca-1d01313c61a7@lunn.ch> References: <20260923-allwinner-a733-gmac-support-v3-0-15735155a789@baylibre.com> <9cc61625-47c9-4bdf-97f0-0528f661a399@lunn.ch> <1j7bkb9h5k.fsf@starbuckisacylon.baylibre.com> <5fae3b42-552a-458a-9710-927360e58c37@lunn.ch> <1jv77u8yak.fsf@starbuckisacylon.baylibre.com> <491f043e-6dc6-4936-a490-31a3362c5b6e@lunn.ch> <1jse2x91oh.fsf@starbuckisacylon.baylibre.com> <1jecec3xnd.fsf@starbuckisacylon.baylibre.com> <93870bce-b18e-4eed-a9ca-1d01313c61a7@lunn.ch> Date: Tue, 29 Sep 2026 19:15:32 +0200 Message-ID: <1ja4p03rnv.fsf@starbuckisacylon.baylibre.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On mar. 29 sept. 2026 at 18:10, Andrew Lunn wrote: >> Thanks for the heads up. So if I'm reading the doc correctly the PHY >> adds 2ns >> * on RX if there a 4.7k pull-up on RXD0 >> * on TX if there a 4.7k pull-up on RXD1 >> >> The schematics for the board are available here [1] >> >> * 4.7k pull-up on RXD0: so we should have 2ns Rx from the PHY >> * 4.7k pull-down on RXD1: no idea what this does. Presumably no delay ? >> >> I've cross-checked the HW, the resistors are actually fitted as the >> schematic says they are. >> >> With the HW setup, the MAC setup that works for me remains >> >> tx-internal-delay-ps = <1620>; >> rx-internal-delay-ps = <1800>; > > These values suggests there are delays on both Rx an Tx. I did not mean to suggest :) To be clear, we have no control over the PHY delay. The strapping/doc says the PHY provide 2ns on Rx, none on Tx (presumably) But I must add 1.62ns on Tx and 1.8ns on Rx through the MAC for the link to work properly (the values above). I don't have an explanation for this. I assume the PHY actually adds no delay, maybe the strapping implementation is broken. Maybe the PCB the already adds a little delay which is why the MAC just need to add a little less than 2ns. > >> >> I know it is not aligned with what it expected but still. > > I'm flexible, if in the end this is what is required, that is fine. It > will need a comment explaining why it is needed, why the guidelines > are not being followed. > > Where i have real problems is with developers who don't respect what > the guidelines say, even when their hardware could do what is > asked. They just do the minimum to make it work, and call it done. > > The comment is then important, because i don't want developers using > this as an excuse not to do the correct thing. Sure, no problem. I'll add a comment in DT when I'll submit it, explaining what we have found regarding the PHY strapping and effects. > > Andrew -- Jerome