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 76E8BC25B76 for ; Sat, 8 Jun 2024 16:50:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: 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=YQvmJkmfFtdFx4U++KpZyB3rLZ06U4V0RBOzTnHSSAA=; b=PJJTCnV+/zt8fe +/5EaYL6NLXooLN7lkxPinprMARgqiZsLsdilZFcpSEkQBorQg/DCOI3RzUweXZ42morJHEuijzss sYSKBfoc5QgiCz7CUTMNk3YmWw9D4m7wP0Ux1WbY0FHOYxIFRwdX+qzsnOn6JHcn1UqyG5+mJdP6S fMwEFAPWF2bX+2hfits4u7xz56GgruI52/SrxmUfTmHzLqWEwt4bN3MlCKzmMCNmMLDoncQYdCR+V nOQaRURo8ZavukaNYSJs8yP4ogba7+If/exrsf/1YjgFfsuxsc3gCFIGqfEYDYPp/tGK4hBz5c1en P8Hxwydii74yMYOTHGgw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sFzGj-00000000N9X-052o; Sat, 08 Jun 2024 16:50:17 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sFzGf-00000000N8v-2zcl for linux-arm-kernel@lists.infradead.org; Sat, 08 Jun 2024 16:50:15 +0000 Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id C8B0E4CA; Sat, 8 Jun 2024 18:50:00 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1717865401; bh=QgS5qJIzriFvn4pqiJgPYNG7GRqG9zYmYqqA+pBaoF8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TCF/3c39cmM/y8y2k+elenMr5rLz1b5fzuh/oiTQPNDTf72Ni2IneruBaJobfyIgY ObZSj+mO6uv95SxRnmoyJ0SUEHSsi7hWX6cS+dCLOcQKEhP4/1EIuDsXES+bChVPL1 NmQHrE/F0WvoX78gNEYbyG0XKiUOxHeKfLlWtFKQ= Date: Sat, 8 Jun 2024 19:49:52 +0300 From: Laurent Pinchart To: Ahmad Fatoum Cc: linux-arm-kernel@lists.infradead.org, imx@lists.linux.dev, devicetree@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Shawn Guo , Li Yang , Marco Contenti , Nate Drude , FrancescoFerraro , Harshesh Valera Subject: Re: [PATCH v2 3/4] arm64: dts: freescale: Add support for the Variscite i.MX8MP DART8MCustomBoard Message-ID: <20240608164952.GE18479@pendragon.ideasonboard.com> References: <20231025165058.31697-1-laurent.pinchart@ideasonboard.com> <20231025165058.31697-4-laurent.pinchart@ideasonboard.com> <314ad280-e3e8-4087-8862-439cf45aa0f9@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <314ad280-e3e8-4087-8862-439cf45aa0f9@pengutronix.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240608_095014_388860_445E870E X-CRM114-Status: GOOD ( 15.48 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Ahmad, On Mon, Nov 27, 2023 at 07:07:16AM +0100, Ahmad Fatoum wrote: > On 25.10.23 18:50, Laurent Pinchart wrote: > > The DT8MCustomBoard is a carrier board for DART i.MX8-based modules. > > This device tree file adds support for the DT8MCustomBoard v2.0 with a > > connected DART-MX8M-PLUS module. > > > > Signed-off-by: Laurent Pinchart > > --- > > > > +&eqos { > > + mdio { > > + ethphy1: ethernet-phy@1 { > > + compatible = "ethernet-phy-ieee802.3-c22"; > > + reg = <1>; > > + eee-broken-1000t; > > + reset-gpios = <&gpio_exp_2 0 GPIO_ACTIVE_LOW>; > > + reset-assert-us = <10000>; > > + reset-deassert-us = <20000>; > > Ouch. So you have a PHY at address 0 (broadcast address) and a PHY at address > 1 on the same bus? I think it's worth a comment whether broadcast for this > PHY here is disabled by strapping or in the bootloader. This particular PHY is an ADI1300. The schematics indicates: LEDs - active HIGH, address 00001b SOM PHY MDIO address 00000b I tried to investigate, and I haven't found any mention of address 0 being a broadcast address in the ADIN1300 documentation. Trying to dig a bit more, I've read clause 22 of the IEEE 802.3ak specification and found this: 22.2.4.5.5 PHYAD (PHY Address) The PHY Address is five bits, allowing 32 unique PHY addresses. The first PHY address bit transmitted and received is the MSB of the address. A PHY that is connected to the station management entity via the mechanical interface defined in 22.6 shall always respond to transactions addressed to PHY Address zero <00000>. A station management entity that is attached to multiple PHYs must have prior knowledge of the appropriate PHY Address for each PHY. Section 22.6 defines a 40-pin physical connector, which is not applicable here. I've also found https://ieee802.org/3/10G_study/email/msg03514.html which states "People have made all kinds of wild assumptions about the way MDIO/MDC work in the past. Some people actually believe that PHYADD <00000> is a broadcast address." -- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel