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 7C91DC369D7 for ; Thu, 24 Apr 2025 12:07:31 +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=dIvPXdQKZDqfBdhJUUNkyfS3h78xf0CmbbJ5p0gZbuQ=; b=LUsdD0O+RuvYAZjeRYRiLbe7Nl XAj3QpbW5TzbkVfmftccofacNJTLgnj9Xivg0rUdaBYnxjWGL3Il/6OOJe9d/3yinaDOpdVJaNQWL xEYorMbRCLQzhp41i67tC20HyLl99hOlS4/2Vg6lPUx/sIhhh+IC4oXE582ZKv2JlZHbEB2fU/V/O UfeaNp3KWIgKFmJ3RLEF0TS6GokevXWt0pWgJVZr/8JzPyg9oEnaoI0gnP7o+dY2NZZo/KhYNbOZg O5HC6/pcCJVodHcYuUHuyqSRWlviSWh2y69+rRyTCbvt8g3SA5qaTQ5LvOXKZsYi08BARS2QYtFnR Au9QBBcQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u7vMR-0000000DxqU-2cPE; Thu, 24 Apr 2025 12:07:23 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1u7tSO-0000000DblZ-1STI for linux-arm-kernel@bombadil.infradead.org; Thu, 24 Apr 2025 10:05:24 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=dIvPXdQKZDqfBdhJUUNkyfS3h78xf0CmbbJ5p0gZbuQ=; b=hasb/4sw7LmyLY4HU0iGqP2yVd TyoW53yqIN21buFvq0HesHjcCGBTB8GAww5teyjhCQ2QhIKGYqMRJYKnRU736Ch9ImrtRSG5YcpZe 7MGRo9qubtTsMVK8U55X67bOxaNmzmZbnCSG9xllJ6Scj/YoeEz/C9yQ8x/qR480I2UfIGCq+87PC 6TG9SHCWNtR6sBEPSeqiNBT3IH8WACaLqbN9NN/rvmssl+gv6qj1eWl4NzAdKzZrM1pFGQ2AdwbI0 Z44NA32b+QB9PBplzplj9CViiryQ9bhlaVNBMaukDoCZ//sYB52uPiB4aifJoQxZ3hKAYHv8863vk K1GldL1A==; Received: from woodpecker.gentoo.org ([140.211.166.183] helo=smtp.gentoo.org) by desiato.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1u7tSL-0000000BijN-21kq for linux-arm-kernel@lists.infradead.org; Thu, 24 Apr 2025 10:05:23 +0000 Received: from localhost (unknown [116.232.18.95]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dlan) by smtp.gentoo.org (Postfix) with ESMTPSA id 9CCA2340DF9; Thu, 24 Apr 2025 10:05:18 +0000 (UTC) Date: Thu, 24 Apr 2025 10:05:14 +0000 From: Yixun Lan To: Andre Przywara Cc: Andrew Lunn , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Maxime Ripard , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH 4/5] arm64: dts: allwinner: a527: add EMAC0 to Radxa A5E board Message-ID: <20250424100514-GYA48784@gentoo> References: <20250423-01-sun55i-emac0-v1-0-46ee4c855e0a@gentoo.org> <20250423-01-sun55i-emac0-v1-4-46ee4c855e0a@gentoo.org> <20250424014120.0d66bd85@minigeek.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250424014120.0d66bd85@minigeek.lan> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250424_110521_781451_C5EA69CF X-CRM114-Status: GOOD ( 19.19 ) 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 Hi Andrew, Andre, On 01:42 Thu 24 Apr , Andre Przywara wrote: > On Wed, 23 Apr 2025 18:58:37 +0200 > Andrew Lunn wrote: > > Hi, > > > > +&emac0 { > > > + phy-mode = "rgmii"; > > > > Does the PCB have extra long clock lines in order to provide the > > needed 2ns delay? I guess not, so this should be rgmii-id. > > That's a good point, and it probably true. > > > > > > + phy-handle = <&ext_rgmii_phy>; > > > + > > > + allwinner,tx-delay-ps = <300>; > > > + allwinner,rx-delay-ps = <400>; > > > > These are rather low delays, since the standard requires 2ns. Anyway, > > once you change phy-mode, you probably don't need these. > As I tested, drop these two properties making ethernet unable to work, there might be some space to improve, but currently I'd leave it for now > Those go on top of the main 2ns delay, I guess to accommodate some skew > between the RX and TX lines, or to account for extra some PCB delay > between clock and data? The vendor BSP kernels/DTs program those board > specific values, so we have been following suit for a while, for the > previous SoCs as well. > I just tried, it also works with some variations of those values, but > setting tx-delay to 0 stops communication. > I'd not bother to try other combinations, and just stick to vendor's settings thanks -- Yixun Lan (dlan)