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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 DE7E5C432BE for ; Thu, 29 Jul 2021 07:07:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD99261054 for ; Thu, 29 Jul 2021 07:07:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234420AbhG2HHY (ORCPT ); Thu, 29 Jul 2021 03:07:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234268AbhG2HHV (ORCPT ); Thu, 29 Jul 2021 03:07:21 -0400 Received: from mail-il1-x12a.google.com (mail-il1-x12a.google.com [IPv6:2607:f8b0:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 331BBC061757 for ; Thu, 29 Jul 2021 00:07:18 -0700 (PDT) Received: by mail-il1-x12a.google.com with SMTP id q18so4753215ile.9 for ; Thu, 29 Jul 2021 00:07:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=engleder-embedded-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=i7tWRI2/pBsm3KiewYI+IUt6wiFkejoi1mmnLILvYmc=; b=sT5JTE6XinjkASQnvhqTkRgdbM2Plu97ocAZcRrBRdX+ZThyfzmnZXDm2cxJ8XGYI8 2HznEkK46F2ghVgtKcIbNSoFjtIzhHnsXZqn6C7P57bXHiEeKf7vOWG42FCBDgiL+GE4 nJ+stW5ratEg+5YpD3qlqgHxuVuYlogWDwIwoXVm/N2xRQ9CVkoX+eRrqCdCNdb1Ai2q cWept1McEdaQ/3F8JEFiGn6E/O8q8NeV+MkjQXYt5m02WYcX/7qKZP5S4e6WKkkjEFn/ F1nfWwhh+Jli0PlcLkGy2fFrUVwCVPsHL8KLDT7m2gQEggFRXP8J4SCWaaWv8zRjPvIh esfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=i7tWRI2/pBsm3KiewYI+IUt6wiFkejoi1mmnLILvYmc=; b=DviSfZF2jYDRJ3nXIp8N5GFaH03TrsXrMOL9PtkZo0SLdgvHzrWWL0HqC0j/izmq4i h0sAHxvJ4bpg0oyDWj466CjiPd3eoPrx6H+J0BQVZX/G9E5bUY7dpvYdEKaZhjpM3xaG ZhS6SZh6+4cV3wrxJjsW3k+rpCfnKlmFqTtabYxBuKq3lLJb7Ipai7tveK/AocfHK6Fs 8mlAr/5LooXUt0LOhDRT9W4K+TwGNXszng0M1/NXgFOjdS8YiM8qiq0H/zLT5KrUoJqO newaZaarXtij/9SWavR7JzXDn+JXmogrma27f66AtrDBcee/jflXxkLssdwm+VBCXXlb 8vZg== X-Gm-Message-State: AOAM531BhX9AMm12JEzZMxfGNuwpD2XLVKEykSpGq4ovq5GBHvAER3JE m3f5yv5JI7DRgPovwDIkLfqagkCHwI5/JNLtATB+lA== X-Google-Smtp-Source: ABdhPJygcOzVJpOIGLdlyW/c4B2i5pB2/N0Hgv6RXIUsYWMi5xQM67oaenWnR+ocJnNBnz6lvlGXhc4JKOzyHSCAqvw= X-Received: by 2002:a92:cec5:: with SMTP id z5mr2493504ilq.226.1627542437600; Thu, 29 Jul 2021 00:07:17 -0700 (PDT) MIME-Version: 1.0 References: <20210726194603.14671-1-gerhard@engleder-embedded.com> <20210726194603.14671-3-gerhard@engleder-embedded.com> <2a151f9a-f743-31f4-a4c1-cdf15daf1b67@xilinx.com> In-Reply-To: <2a151f9a-f743-31f4-a4c1-cdf15daf1b67@xilinx.com> From: Gerhard Engleder Date: Thu, 29 Jul 2021 09:07:06 +0200 Message-ID: Subject: Re: [PATCH net-next 2/5] dt-bindings: net: Add tsnep Ethernet controller To: Michal Simek Cc: Rob Herring , David Miller , Jakub Kicinski , netdev , devicetree@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Jul 29, 2021 at 7:07 AM Michal Simek wrote: > On 7/28/21 10:14 PM, Gerhard Engleder wrote: > > On Wed, Jul 28, 2021 at 12:55 PM Michal Simek wrote: > >>>>>>>> + - enum: > >>>>>>>> + - engleder,tsnep > >>>>>>> > >>>>>>> tsnep is pretty generic. Only 1 version ever? Or differences are/will > >>>>>>> be discoverable by other means. > >>>>>> > >>>>>> Differences shall be detected by flags in the registers; e.g., a flag for > >>>>>> gate control support. Anyway a version may make sense. Can you > >>>>>> point to a good reference binding with versions? I did not find a > >>>>>> network controller binding with versions. > >>>>> > >>>>> Some of the SiFive IP blocks have versions. Version numbers are the > >>>>> exception though. Ideally they would correspond to some version of > >>>>> your FPGA image. I just don't want to see 'v1' because that sounds > >>>>> made up. The above string can mean 'v1' or whatever version you want. > >>>>> I'm fine if you just add some description here about feature flag > >>>>> registers. > >>>> > >>>> Don't Xilinx design tool (vivado) force you to use IP version? > >>>> Normally all Xilinx IPs have certain version because that's the only way > >>>> how to manage it. > >>> > >>> Yes I use an IP version in the Xilinx design tool. I use it as a version of the > >>> VHDL code itself. In my case this version is not related to the > >>> hardware software > >>> interface. The goal is to keep the hardware software interface compatible, so > >>> the IP version should not be relevant. > >> > >> I expect this is goal for everybody but it fails over time. We normally > >> compose compatible string for PL based IP with IP version which is used. > >> And it is quite common that couple of HW version are SW compatible to > >> each other. > >> It means use the same HW version as you use now. When you reach the > >> point when your HW IP needs to be upgraded and will require SW alignment > >> you have versions around which can be used directly. > > > > I would like to follow the argument from Rob: > > "The above string can mean 'v1' or whatever version you want." > > If there ever is an incompatible new IP version, then a new compatible string > > can be added which means 'v2'. E.g. for 128bit physical address support I > > would choose the compatible string 'engleder,tsnep128'. I don't see an > > advantage in adding a version number to the compatible string. > > > > This IP will be used in products where compatible hardware is a must. > > An IP upgrade which requires SW alignment will result in heavy complaints > > from the customers. Such an IP upgrade would result in a new IP. > > Like for shared libraries, an incompatible API change is similar to a new > > library. > > From my point of view where I expect the most of customers are using > Xilinx DTG (device tree generator) compatible string is composed with IP > name and version used in design tool. This is unique combination which > properly describes your HW. > And choosing different compatible string or string without version is > breaking this connection between hw design tool and sw. > > From my perspective it is much simpler to understand that your HW ip > called ABC-rev1 requires DT node which is your_company,ABC-rev1 instead > of any made name. > But up2you - you will be talking to your customers. Thanks for explaining your point of view. From my side I don't expect that Xilinx DTG is used. The few people I know who are working with Zynq/ZynqMP are using the Xilinx tools only to generate the bitstream. This way you are able to do software development for the Zynq/ZynqMP like for any other hardware platform. Thanks for your Feedback! Gerhard