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 5E407C9830D for ; Wed, 23 Sep 2026 22:15:31 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: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=mLaZ6QMAlChH6Bas+cLTUExn52jNXV5CR8pfGjWWblA=; b=2iZHpVdy/7mS18Xb4eCmWowb+Z sRzuJjW/kTBTbwBLiFBjOCkmEuJ4fgAYuVXt+EG/5ZFoAepoM/jcnjjl72zUZmSefEp1tz+vCBaYL F+f/g6j1wpC9gJweA+ZXa5Tr3DLsVbQqYDK6gPgJKoZKTx/HSzkkIc6IWWChegmJFLaQlAQnRiopt LO5C/Mplu4p/e4HChMY49hHCz6EE14MMblMKKkBlGsDy/tXOezyGQ+S+WB2Gh7O+HU6r1/5WfHCHK E29gWXYoTDuRBgwQcNV8xYc26nLlQoqS947uZSzjAUhw4b9Zw6ax2WTBbrgyShIoqb4+DyelmHj7/ 2LENiJuw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9VFJ-00000009dLD-3E7f; Wed, 23 Sep 2026 22:15:21 +0000 Received: from vps0.lunn.ch ([156.67.10.101]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9VFH-00000009dKg-1A3L for linux-arm-kernel@lists.infradead.org; Wed, 23 Sep 2026 22:15:20 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=mLaZ6QMAlChH6Bas+cLTUExn52jNXV5CR8pfGjWWblA=; b=iNuptB2oIZhXrkQPyxHmWroghF onbceDSy5Aw6UTSEruhdhedVchiiIiwpBpcRkJDV/IenuwgLaaqGZbwrdhek5HrabtFtYXPJLVxWf lYJJOVf2J2fSDQ/JN6oPtHWm/32fpHCs+FIKA/vR4iq+yjUE6NcQ0vRgjjy8iLA4RirA=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1x9VF2-006sqK-7V; Thu, 24 Sep 2026 00:15:04 +0200 Date: Thu, 24 Sep 2026 00:15:04 +0200 From: Andrew Lunn To: Jerome Brunet 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 Message-ID: References: <20260923-allwinner-a733-gmac-support-v3-0-15735155a789@baylibre.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260923-allwinner-a733-gmac-support-v3-0-15735155a789@baylibre.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260923_151519_320724_709F5680 X-CRM114-Status: GOOD ( 11.87 ) 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 > * Tx-delay: The vendor kernel ships with a Tx delay of 2.16ns. It may seem > to work at first but breaks under heavy load. The vendor kernel is > configured for an external RGMII clock, which cannot work on the A7A: > the 125MHz input and 25MHz reference output are not wired to the PHY. > It was most likely not tested on this board. A 1.62ns Tx delay works > well. > > DT example is available here (gated on CCU and pinctrl mainline support > currently): > https://github.com/jbrun3t/linux/commit/aa6f3a5ce4cd6e09ff9be1828915bfe8e87c57df &gmac0 { phy-mode = "rgmii-id"; phy-handle = <&ext_rgmii0_phy>; phy-supply = <®_swout1>; pinctrl-names = "default"; pinctrl-0 = <&gmac0_pins>; tx-internal-delay-ps = <1620>; rx-internal-delay-ps = <1800>; Something does not seem correct here. rgmii-id means the PHY is adding 2ns of delay. The MAC is adding an additional 1.6 to 1.8 ns. The total is way too big when the standard says 2ns. Is the PHY adding 2ns? Andrew