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 B6E19CA1013 for ; Thu, 18 Sep 2025 14:52:14 +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-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ScdLUi7Tz/pPrIV0NjyW4U23VIueAMMWyx8pCW4VZCI=; b=YQ8XN5DQEuPWFt96dCbX/pERWB OmYACgQLiAiAwATsTqZHteSmFXCRa+dMeTf5H84lK/TI04t/2mddgvheHneaPmkd4eApSysru8Obs yZfX84sIbLW/Z37QdFwIiSpAe7dE1vfRLpfxmhRBc10sVAq+aTAQEx9QRKRXqLVrufEU7id8/vEz5 7U0M2BG1S4rUfyDEm+smDz0V4S1XdV6MNL+D6UNkcFGyO3YlRaUY83Nxh6r95ZYGg74aPmOWCPRMY 4aA/PKAAYo8g0qKfynev2tamSs2LTW1dPg/Q99gqmXjRiEs01KhLxHetplINawn2XZFl8+zmwXTcp Fh37EPxw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uzFzS-00000000DMR-2cpE; Thu, 18 Sep 2025 14:52:06 +0000 Received: from smtp15.bhosted.nl ([2a02:9e0:8000::26]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uzFzQ-00000000DLJ-0YDd for linux-arm-kernel@lists.infradead.org; Thu, 18 Sep 2025 14:52:06 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonic.nl; s=202111; h=content-transfer-encoding:content-type:mime-version:references:in-reply-to: message-id:subject:cc:to:from:date:from; bh=ScdLUi7Tz/pPrIV0NjyW4U23VIueAMMWyx8pCW4VZCI=; b=kIabRhxvNKZM0EOI0x7ezn3kFDiHT7Qm8gIvQ0BYtJpuVmeKcBUdD0GswFJM4ppsDTAfe2nGvvNzW EXD8tBZpck/HdmqTgASPLT6zjPnhfW3/RUZoI4rvTNKJWHwAwbHtRCS6+DhaCeZlMw5IfwJYZIDLbv yFmJKLYi1x+eMUSaqnjmy9vIa1tanmteksbq2doEgc7rmR2DgCCx8crqZVfC+RlwGFmiNWbIBl4xWb 9hNRV0yBO/HZHtotQkzznJ1DRPpbuM1Z29ahTt8cX/J5e94fqC11tRXXsFVnIUte9MEJLYq6n/Hq7j UdYFbNO1fjxZ0AANHx3zEmpP069LWnA== X-MSG-ID: 05ec3115-949f-11f0-9d65-00505681446f Date: Thu, 18 Sep 2025 16:51:56 +0200 From: David Jander To: Andrew Lunn Cc: Jonas Rebmann , Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Liam Girdwood , Mark Brown , Shengjiu Wang , Shawn Guo , Sascha Hauer , Fabio Estevam , Pengutronix Kernel Team , Vladimir Oltean , netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sound@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Lucas Stach , Oleksij Rempel Subject: Re: [PATCH v2 3/3] arm64: dts: add Protonic PRT8ML board Message-ID: <20250918165156.10e55b85@erd003.prtnl> In-Reply-To: References: <20250918-imx8mp-prt8ml-v2-0-3d84b4fe53de@pengutronix.de> <20250918-imx8mp-prt8ml-v2-3-3d84b4fe53de@pengutronix.de> Organization: Protonic Holland X-Mailer: Claws Mail 4.3.1 (GTK 3.24.49; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250918_075204_580905_4A845E44 X-CRM114-Status: GOOD ( 11.80 ) 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 Thu, 18 Sep 2025 16:14:28 +0200 Andrew Lunn wrote: > > + port@4 { > > + reg = <4>; > > + ethernet = <&fec>; > > + label = "cpu"; > > + phy-mode = "rgmii-id"; > > + rx-internal-delay-ps = <2000>; > > + tx-internal-delay-ps = <2000>; > > + > > + fixed-link { > > + full-duplex; > > + speed = <100>; > > + }; > > + }; > > + }; > > + }; > > +}; > > + > > +&fec { > > + pinctrl-names = "default"; > > + pinctrl-0 = <&pinctrl_fec>; > > + phy-mode = "rgmii"; /* switch inserts delay */ > > + rx-internal-delay-ps = <0>; > > + tx-internal-delay-ps = <0>; > > + status = "okay"; > > + > > + fixed-link { > > + full-duplex; > > + speed = <100>; > > + }; > > You have an RGMII interface, but you run it at 100Mbps? That might be > worth a comment somewhere to explain why. Yes, unfortunately the SJA1105Q does not support PAUSE frames, and the i.MX8MP FEC isn't able to sustain 1000Mbps (only about 400ish) due to insufficient internal bus bandwidth. It will generate PAUSE frames, but the SJA1105Q ignores these, leading to packet loss, which is obviously worse than restricting this link to 100Mbps. Ironically both chips are from the same manufacturer, yet are incompatible in this regard. Best regards, -- David Jander