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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 20122CA5FA5 for ; Tue, 29 Sep 2026 17:15:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=gliMXdJJkSbMhSXEgRAl5Ekvovgp6Cfw/QE4Z+KNG5E=; b=zog+40uaanuLX5iv1boZoGh+8r 59f9RFblYhz79WYGjrjH90xuojDAHOqUj+3ePumuf5d0lLh5G4SDewSoP8gNz7zem/KGNv10frett MV+12Rr7uUAeB0sMV7K5kuaGNql8YHrtiFzwjRV6xxxczFbVNbqfuIsRCI0p8d9JsEhPUyqIa6ohX +pq0fnKjRMMtzKG2ZArfm2pVrQFMbpfajx1x/iKS8moVpfLNgK9a7sS5PTaqeR1JogyyNHxusf0gf r2VP5iGfjBrPq0gLZjFzyCfFXCCvOVdHzFcv3pt8ZOWI5hz/Bqt4JBYXOc1MBNgloc17uBqQ0l7+B sa+22GlQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBbQY-000000049oK-2Nwt; Tue, 29 Sep 2026 17:15:38 +0000 Received: from mail-wm2-x10.google.com ([2a00:1450:4864:31::10]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBbQV-000000049nV-2W74 for linux-arm-kernel@lists.infradead.org; Tue, 29 Sep 2026 17:15:37 +0000 Received: by mail-wm2-x10.google.com with SMTP id 5b1f17b1804b1-49e6598dd44so28615025e9.1 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=lists.infradead.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=IBCdT73KYWpJNrYOkhyMz+lW7N/hZ2y088NYPc5stFgHoQvNUDtOcZmVFAzkJu5hW/ QCMkCeESLTKt06yYJ1GUxtf+/mW3Med98mSZ/dGHUGJVYbEbUO3NH0/OTdy+anP65m7I 6KEoJeBmuw6W+ZFRGeKSJQ3BXLtLMtf0C46HpHtij1XLKidmp80bKVutU+6x8F6tFZOG ngNXQuZZLeiPGkXrkwb6x/C/BESMwyVhhJgsziUq5+rNNBvbPxY8pGkwd2fI5DquwM10 JcQlOQ4eqVYlHsZtiLCHfvWtggLqd8XdpGXU0Fs/fd14hffU4h8A/tzS4+acJRmKPl7y kPWQ== 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=0I9Z4hHjLQzs0wVAH8Fjs6xkJSsiAfhmmn6cHnVVeqv78wPFElsW74V6biYrjIpqK3 idYng7PkREN1L83H5T2A0WHhBWqHRuQnoc4GRMkIeOuvFRuFvkXDt3lHp48A811DvcV3 +d9vUYhXtDaNJqQuq9bhtLGMhDR1GUfhjEXWOCI39X35HbzqFPJo8LCdPcY7IBNgnFQM Fwh9Gqa5uPubD4GLXkPb2dsOlo+S7Qpj2NKUp3KroFN1IdwaPv2HeWPnBNuT9NFwGpbj hwgNpE37kxAs/x8sby9MavhATvEFK05ZN/gsK28FDNogbCZiBxg3UgJORHe9Ut4FwjHw SXNg== X-Forwarded-Encrypted: i=1; AKwUvBzfMQur/EFzUYYiOb6UpHuXQ9g9kxLb1fuh2qugmCNoqAfhr+/EmxAemYMi9oAJX58sm8r1ZflfAV3E0PUQQJ5y@lists.infradead.org X-Gm-Message-State: AFuF++k4IHmmfGWcz3b2S6FD0N/q6Ohq8jbAMdJ/Z1ka35T7sIxLT1vr AWQfdpXUmOlHLEC4QPJHONoRu4T3927l45OAlBNTZicVGGmYho9u+NQEmrAO5loHlWo= X-Gm-Gg: AYBFou3+KO/74sdgM0+0Ubqn2y2PjP6EcxTYKVlu+jwo97x+Z6OH5LWw8MjD/zJ/WmT jHL6hNJ+BKOmZiO81Dgy0fRpiTf/ZGRzOOzdEwxTRDZmPQblwxVrY8Q5k3kmQKQ9wi+kuLA2L87 StQRm7lxvTBJv1KaYgqqAVz7voNqqMRHcsWEzkWMtgpFzwp/BKE6Oxg3Qn53LkK6fy9P731iRzg FdSsfXDso9Tzr++MTCdnWKIZgeGl15gFNxzr2QoSYphmLPGpjdV/G+gpzTAmoVunA7SPwsIJhpX bZahy2jByDsQJKSq/qqCOTWJ/O47XzsObPVS/5GGmHNAUyHl8WqCev9cbr/EM8TUEAi40fNamu/ igdhm9yr4DxRyU9VatUmXUEy1MZWBfI7rZIe412olc6BOmKg623GkDjeROjpTbjBBsQAHNcr64S Frits/AGep8CltVP6MzikgD6oYS5LxAU3HobymrqTjHKZhdcFVQAvOInHdSpYHt1lFFkdCGh7cY Mf6P6zWgTqFo8OvwQ== 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> MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260929_101535_655415_CCDCE62C X-CRM114-Status: GOOD ( 24.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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