From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C62D168DE for ; Fri, 3 Nov 2023 12:53:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [IPv6:2a0a:edc0:2:b01:1d::104]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F4D5CE for ; Fri, 3 Nov 2023 05:53:10 -0700 (PDT) Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qytff-0007Wx-6h; Fri, 03 Nov 2023 13:53:07 +0100 Received: from [2a0a:edc0:2:b01:1d::c0] (helo=ptx.whiteo.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qytfe-006Jv8-9h; Fri, 03 Nov 2023 13:53:06 +0100 Received: from ore by ptx.whiteo.stw.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1qytfe-000CD8-6q; Fri, 03 Nov 2023 13:53:06 +0100 Date: Fri, 3 Nov 2023 13:53:06 +0100 From: Oleksij Rempel To: Andrew Lunn Cc: devicetree@vger.kernel.org, Fabio Estevam , kernel@pengutronix.de, Shawn Guo , Sascha Hauer , linux-kernel@vger.kernel.org, Rob Herring , NXP Linux Team , Krzysztof Kozlowski , =?utf-8?B?U8O4cmVu?= Andersen , Sam Ravnborg , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 2/2] arm64: dts: freescale: Add SKOV IMX8MP CPU revB board Message-ID: <20231103125306.GB40819@pengutronix.de> References: <20231103105305.2459143-1-o.rempel@pengutronix.de> <20231103105305.2459143-2-o.rempel@pengutronix.de> <1ee285d7-6bc9-43ad-9ec9-a8aaed4452b5@lunn.ch> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1ee285d7-6bc9-43ad-9ec9-a8aaed4452b5@lunn.ch> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: devicetree@vger.kernel.org Hi Andrew, On Fri, Nov 03, 2023 at 01:35:46PM +0100, Andrew Lunn wrote: > > + port@2 { > > + reg = <2>; > > + label = "cpu"; > > + ethernet = <&eqos>; > > + /* 2ns rgmii-rxid is implemented on PCB. > > + * Switch should add only rgmii-txid. > > + */ > > Its unusual to actually see that. Its even more unusual its only one > clock line. Can you actually see it on the PCB? Yes. I even made a delay calculation by measuring this trace on PCB, just to make sure I see it correctly. > > + phy-mode = "rgmii-txid"; > > + tx-internal-delay-ps = <2000>; > > Is this actually needed? rgmii-txid should add 2ns delay. Since this > apparently works, i'm assuming setting tx-internal-delay-ps to 2ns > does nothing, otherwise you would have a 4ns delay. Without it the driver will complain: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/dsa/microchip/ksz_common.c?h=v6.6#n3496 but it works as expected. Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |