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, 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 3960DC433DB for ; Sun, 28 Mar 2021 15:25:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AD1B61974 for ; Sun, 28 Mar 2021 15:25:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231366AbhC1PZS (ORCPT ); Sun, 28 Mar 2021 11:25:18 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:51852 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231149AbhC1PYx (ORCPT ); Sun, 28 Mar 2021 11:24:53 -0400 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1lQXHQ-00DTKW-JA; Sun, 28 Mar 2021 17:24:44 +0200 Date: Sun, 28 Mar 2021 17:24:44 +0200 From: Andrew Lunn To: Tobias Waldekranz Cc: davem@davemloft.net, kuba@kernel.org, vivien.didelot@gmail.com, f.fainelli@gmail.com, olteanv@gmail.com, netdev@vger.kernel.org, robh+dt@kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH net-next 1/3] net: dsa: mv88e6xxx: Allow dynamic reconfiguration of tag protocol Message-ID: References: <20210326105648.2492411-1-tobias@waldekranz.com> <20210326105648.2492411-2-tobias@waldekranz.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210326105648.2492411-2-tobias@waldekranz.com> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, Mar 26, 2021 at 11:56:46AM +0100, Tobias Waldekranz wrote: > All devices are capable of using regular DSA tags. Support for > Ethertyped DSA tags sort into three categories: > > 1. No support. Older chips fall into this category. > > 2. Full support. Datasheet explicitly supports configuring the CPU > port to receive FORWARDs with a DSA tag. > > 3. Undocumented support. Datasheet lists the configuration from > category 2 as "reserved for future use", but does empirically > behave like a category 2 device. > +static int mv88e6xxx_change_tag_protocol(struct dsa_switch *ds, int port, > + enum dsa_tag_protocol proto) > +{ > + struct mv88e6xxx_chip *chip = ds->priv; > + enum dsa_tag_protocol old_protocol; > + int err; > + > + switch (proto) { > + case DSA_TAG_PROTO_EDSA: > + if (chip->info->tag_protocol != DSA_TAG_PROTO_EDSA) > + dev_warn(chip->dev, "Relying on undocumented EDSA tagging behavior\n"); > + > + break; > + case DSA_TAG_PROTO_DSA: > + break; > + default: > + return -EPROTONOSUPPORT; > + } You are handling cases 2 and 3 here, but not 1. Which makes it a bit of a foot cannon for older devices. Now that we have chip->tag_protocol, maybe we should change chip->info->tag_protocol to mean supported protocols? BIT(0) DSA BIT(1) EDSA BIT(2) Undocumented EDSA Andrew