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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91B7EC433DF for ; Mon, 22 Jun 2020 12:02:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7114F2071A for ; Mon, 22 Jun 2020 12:02:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727960AbgFVMC2 (ORCPT ); Mon, 22 Jun 2020 08:02:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726889AbgFVMC2 (ORCPT ); Mon, 22 Jun 2020 08:02:28 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0032C061794; Mon, 22 Jun 2020 05:02:28 -0700 (PDT) Received: from p5b06d650.dip0.t-ipconnect.de ([91.6.214.80] helo=kurt) by Galois.linutronix.de with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1jnL9e-00083K-0P; Mon, 22 Jun 2020 14:02:26 +0200 From: Kurt Kanzenbach To: Andrew Lunn Cc: Vivien Didelot , Florian Fainelli , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, Rob Herring , devicetree@vger.kernel.org, Sebastian Andrzej Siewior , Richard Cochran , Kamil Alkhouri , ilias.apalodimas@linaro.org Subject: Re: [RFC PATCH 9/9] dt-bindings: net: dsa: Add documentation for Hellcreek switches In-Reply-To: <20200619135657.GF304147@lunn.ch> References: <20200618064029.32168-1-kurt@linutronix.de> <20200618064029.32168-10-kurt@linutronix.de> <20200618134704.GQ249144@lunn.ch> <87zh8zphlc.fsf@kurt> <20200619135657.GF304147@lunn.ch> Date: Mon, 22 Jun 2020 14:02:19 +0200 Message-ID: <87imfjtik4.fsf@kurt> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Fri Jun 19 2020, Andrew Lunn wrote: >> > The switch is 100/100Mbps right? The MAC is only Fast ethernet. Do you >> > need some properties in the port@0 node to tell the switch to only use >> > 100Mbps? I would expect it to default to 1G. Not looked at the code >> > yet... >>=20 >> No, that is not needed. That is a hardware configuration and AFAIK >> cannot be changed at run time. > > I was wondering about that in general. I did not spot any code in the > driver dealing with results from the PHY auto-neg. So you are saying > the CPU is fixed speed, by strapping? But what about the other ports? > Does the MAC need to know the PHY has negotiated 10Half, not 1G? Would > that not make a difference to your TSN? Indeed, that does make a difference. I've checked with the vendor. The current version of the switch IP does not support configuring the speed etc. at run time. It is hard wired to 100 Mbit/s or 1000 Mbit/s for now. Later versions of the chip might support setting the speed etc. via configuration registers. As a result the PHYs at the front ports should be programmed to only advertise 100 Mbit/s or 1G depending on the hardware setup. Thanks, Kurt --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEooWgvezyxHPhdEojeSpbgcuY8KYFAl7wncsACgkQeSpbgcuY 8KYXyA/8DLXlHC/IIVPn9Frz2Es51NLmJmUYxmNRdlFFtHNlVZ7OxyewgvGG4XBa Y3+UMl9byjXzkHkgYAEBp98PKDtAf+wM2DYj/OP2CS9IvxKL6X1Sfductwxq3yg7 MFOUvHo/eeGd88vFvDddX6/z9NeV2TaXTBmnwLLxsXa06QjTedhM5bJTBRZcqZi/ aHzDXwXgr81HSF3rj2QwlcgjVtUF7NKeSq42AnnuQyw2sfyNEObN0x/85+/FlaWx C7kNUIX/gB8mRjEBDwWb4Ic7K+X2Fry16yMvaSLzDO9oKXeefRt1fAaIL5/e+/MZ HYifNcPEHczfd3SxWQf7qNdm3ulvHTVkbFbAqrENtaqEH7nw6YGgpAjSpAKFynM8 DPp8W9wE+No5Bvm4zxarR/eERItRjruRXwot/tx0D7/Of1QVpPqf1Rt3CfTKphDC ZHvkeZoJAnm6wo6Ig5v7Bq44oTRFTbXjkXgl681BNLk4xJnU0Akvam3nVMDzapH+ rOGyFlcsNk6QE08W2maQjOKmjEclWzXxNpuEc80CgKzseYJOmuvT1Nbt6B7SymZY hdlKz2A9h2rZgMxIlKVGH5QNEE0iLc1wr5N4XQYcZKftveJc6hbx+KIg1HvPcfH5 nWKuH/lHl98iBpzVow48vMcA0++wcy+TCVBM3blbL8ACiMa792Y= =CdRP -----END PGP SIGNATURE----- --=-=-=--