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=-7.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 BD0CFC4743D for ; Fri, 4 Jun 2021 23:18:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A163261359 for ; Fri, 4 Jun 2021 23:18:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231707AbhFDXUp (ORCPT ); Fri, 4 Jun 2021 19:20:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:42808 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229774AbhFDXUn (ORCPT ); Fri, 4 Jun 2021 19:20:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D62CF613EC; Fri, 4 Jun 2021 23:18:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622848737; bh=o5HZTLhP5wQ4KKFNqCChs2/Ti0SXDssVhVvBtp5dayI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CGVHiF4bMBkMEK0K/sxKjF+kBO4UDZkFoIv+fShW7RXBzZOZubgNL1d1nUFEJ/Mtv 0mHCLhI300IJKrWQi1SS7Kfquc1CjZbdj9CleQ9O6vWITg3znvEr9YbI89YHOKJuQL DxlXdf6FodA1XwCH33ZFCELvVw3nsSMnjtv7NRfGzU22y1hSWyDUojZW4Pr4iPOWL1 gDpSPDn6MmpWeXRl9F2iIYzW2LRVjqg13stVUros0lam+qXp38IwbQPJnuly3RIiZP CsrWC1gV8FbzhSWYvQeUJKL3wi8BtVn1RV81jlyqSdI1NshikcaMbFxhiB/WVHmLOE Va9GuKhvvK0Ug== Received: by pali.im (Postfix) id A5169990; Sat, 5 Jun 2021 01:18:54 +0200 (CEST) Date: Sat, 5 Jun 2021 01:18:54 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: "Russell King (Oracle)" Cc: Madalin Bucur , Andrew Lunn , Igal Liberman , Shruti Kanetkar , Emil Medve , Scott Wood , Rob Herring , Michael Ellerman , Benjamin Herrenschmidt , "netdev@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Camelia Alexandra Groza (OSS)" Subject: Re: Unsupported phy-connection-type sgmii-2500 in arch/powerpc/boot/dts/fsl/t1023rdb.dts Message-ID: <20210604231854.qi3o3k4rk23jjetg@pali> References: <20210603143453.if7hgifupx5k433b@pali> <20210603194853.ngz4jdso3kfncnj4@pali> <20210604192732.GW30436@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210604192732.GW30436@shell.armlinux.org.uk> User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Friday 04 June 2021 20:27:33 Russell King (Oracle) wrote: > 802.3 defined 1000base-X which is a fixed 1G speed interface using a > 16-bit control word. Implementations of this exist where the control > word can be disabled. > > Cisco came along, took 1000base-X and augmented it to allow speeds of > 10M and 100M by symbol repetition, and changing the format of the > 16-bit control word. Otherwise, it is functionally compatible - indeed > SGMII with the control word disabled will connect with 1000base-X with > the control word disabled. I've done it several times. > > There exists 2500base-X, which is 1000base-X clocked faster, and it > seems the concensus is that it has the AN disabled - in other words, > no control word. Thank you for a nice explanation! I think that this information should be part of documentation as it could help also other people to understand differences between these modes.