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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,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 6B4CEC3A59E for ; Sat, 24 Aug 2019 15:56:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 372842082E for ; Sat, 24 Aug 2019 15:56:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="J8RGZH42" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727682AbfHXP4j (ORCPT ); Sat, 24 Aug 2019 11:56:39 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:57156 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726769AbfHXP4i (ORCPT ); Sat, 24 Aug 2019 11:56:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=hTxP15quK0Fsei9TgN96TYGXtzGI9FKeO/CZALB5PvE=; b=J8RGZH42qEaKK8NyAP4iV0wvRO KO5GnOoQAg1oOmyKQJAEVzPOLo0h4eBE+R/EUKXhHbO/Fk9JX47kBxaUEzpnkm/+HKZLktuNYiRx9 hkFWSa4CROdlTeBh6qVylT3jji1pCwKilYwQCl2bCtzaQY43oZtZm8MtDUiHovwswZNQ=; Received: from andrew by vps0.lunn.ch with local (Exim 4.89) (envelope-from ) id 1i1YP6-0002aZ-JH; Sat, 24 Aug 2019 17:56:36 +0200 Date: Sat, 24 Aug 2019 17:56:36 +0200 From: Andrew Lunn To: Vladimir Oltean Cc: Marek =?iso-8859-1?Q?Beh=FAn?= , netdev , Vivien Didelot , Florian Fainelli , David Ahern , Stephen Hemminger Subject: Re: [PATCH RFC net-next 0/3] Multi-CPU DSA support Message-ID: <20190824155636.GD8251@lunn.ch> References: <20190824024251.4542-1-marek.behun@nic.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > Will DSA assume that all CPU ports are equal in terms of tagging > protocol abilities? There are switches where one of the CPU ports can > do tagging and the other can't. Hi Vladimir Given the current definition of what a CPU port is, we have to assume the port is using tags. Frames have to be directed out a specific egress port, otherwise things like BPDU, PTP will break. You cannot rely on MAC address learning. > Is the static assignment between slave and CPU ports going to be the > only use case? What about link aggregation? Flow steering perhaps? > And like Andrew pointed out, how do you handle the receive case? What > happens to flooded frames, will the switch send them to both CPU > interfaces, and get received twice in Linux? How do you prevent that? I expect bad things will happen if frames are flooded to multiple CPU ports. For this to work, the whole switch design needs to support multiple CPU ports. I doubt this will work on any old switch. Having a host interface connected to a user port of the switch is a completely different uses case, and not what this patchset is about. Andrew