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 C7B6BC44500 for ; Mon, 6 Jul 2026 21:34:19 +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=KGGKkAUXMo3mYXdgw//fbeNQbfmfA+U4ZlbWmELp4Rs=; b=Uo7j9b4Dl2NYOcB5Ilc/S+R3Ca Xhkn00TPkwORjWmDsKZRVoz4bGLX5BlSARRSXmuU1SIAx7bV5i1EQUQOhYrvgVmhOSGvvIiKilOwj H3KuX4DO/PAmWrT00IocozgaXq7cL5mOPiuAxC5z3G3Cj9HhPBzxjJhsaN3X/t7wKSJqzsKWYVeC5 gnp0OOQND3mIF/f5A40cpq5aPHLoYXtQMRyCxCj0sBaM+/4hSi0Y5QRqoq728ggo/IhmpdfCE69e7 Zn3WBiMqrmnp4lYPbVJAI0uMYQPHKTkiXn6PIZZ+Dq9Tu1oH4LhEqh6tYqR2zuEKtVmG+pM9uiH9E pw3bIfkA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wgqxB-0000000DeLo-126S; Mon, 06 Jul 2026 21:34:13 +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 1wgqx7-0000000DeJf-37j4; Mon, 06 Jul 2026 21:34:10 +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=KGGKkAUXMo3mYXdgw//fbeNQbfmfA+U4ZlbWmELp4Rs=; b=BStsEw0mWdGD6P77NeD7XTo5E+ tMLKRALNTsZjY+dYVGg+pUrA/xfylJQwIVxCtBV/v+NcdUnwcNNlhSbm8OfUZETKQzhumFXLFeL9M /Z+KfqBRJ9XLn7S7jLF2bA2KfbOz8TusckpW/R1qO6zjBNRWMOh+FwMlA7SXymDOCs6s=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1wgqwy-00B4Ax-OS; Mon, 06 Jul 2026 23:34:00 +0200 Date: Mon, 6 Jul 2026 23:34:00 +0200 From: Andrew Lunn To: Pufan Jin <2254650260@qq.com> Cc: Heiko Stuebner , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] arm64: dts: rockchip: Add EmbedFire LubanCat 4 board Message-ID: <647b653e-d602-46d3-bbc1-0d3fa132696e@lunn.ch> References: <20260705135014.1004166-1-2254650260@qq.com> <1ac2d0f4-e027-4633-9d34-2709cb3e43ec@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260706_143409_778615_026EF8E3 X-CRM114-Status: GOOD ( 17.30 ) 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 Tue, Jul 07, 2026 at 05:20:35AM +0800, Pufan Jin wrote: > On Sun, Jul 05, 2026 at 05:11:58PM +0200, Andrew Lunn wrote: > > > + /* The board has 1.5ns delays on RX lines; TX delay is provided by the MAC. */ > > > > That is pretty unusual. How is this RX delay done? > > You're right to question this, and I apologise -- the comment was > inaccurate. I re-checked the board schematic and both TXC and RXC > have ~2ns of trace delay added on the PCB (annotated as > "TXC / RXC : delays 2ns" next to the RGMII bus). O.K. So both having delays on the PCB is what i would call "somewhat unusual", vs "pretty unusual" for a single delay. > Since the PCB already provides the required clock skew on both > directions, for v2 I will switch to: > > phy-mode = "rgmii"; > > and drop both the tx_delay property and the misleading comment. Please correct the comment. One issue we have is that many boards use "rgmii" and are broken. You have a board which uses "rgmii" and it is in fact correct. It is good to explain why it is correct, otherwise people could think it is just another broken board. Andrew