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 C5CDCC43331 for ; Tue, 12 Nov 2019 02:53:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 983CD206C3 for ; Tue, 12 Nov 2019 02:53:18 +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="NAULs/QL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727021AbfKLCxR (ORCPT ); Mon, 11 Nov 2019 21:53:17 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:34948 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726932AbfKLCxR (ORCPT ); Mon, 11 Nov 2019 21:53:17 -0500 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=0N54sqRXV1Q/iG6bSVUkEie2+kD6wQ1JLv31TL/96Ok=; b=NAULs/QLdDy7CLMz7+5IwA/et7 RbOR//q2TRB72vSXbEjqPzrsdAXXn4zwWq2I6LJjASgduMKbqlY+iiFjldQcsIcZwfhyK34aTZbzE LDGoKof6kzU4quGxuFSRsTftnCHhmCzezEWwnUwpBSfiw9YhI+1PvLFK0rGA5fwfP/oA=; Received: from andrew by vps0.lunn.ch with local (Exim 4.92.2) (envelope-from ) id 1iUMIl-0006As-DR; Tue, 12 Nov 2019 03:53:07 +0100 Date: Tue, 12 Nov 2019 03:53:07 +0100 From: Andrew Lunn To: Vladimir Oltean Cc: Florian Fainelli , Jakub Kicinski , "David S. Miller" , Alexandre Belloni , Vivien Didelot , Joergen Andreasen , "Allan W. Nielsen" , Horatiu Vultur , Claudiu Manoil , netdev , Vladimir Oltean Subject: Re: [PATCH net-next 15/15] net: mscc: ocelot: don't hardcode the number of the CPU port Message-ID: <20191112025307.GB8153@lunn.ch> References: <20191109130301.13716-1-olteanv@gmail.com> <20191109130301.13716-16-olteanv@gmail.com> <20191110165031.GF25889@lunn.ch> <20191110171250.GH25889@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > Andrew, is the Z80 embedded CPU able to run Linux? No. If not, then from > what perspective are you saying you're going to call it "the z80 port" > instead of "CPU port", and why would you add support for it? I've wanted to do a Hello World, but never got around to it. I have seen uses cases where it is possible to hot {un}plug the host. The switch keeps on running. While the host is missing, STP packets are no longer sent, but the switch keeps on switching. At some point the other switches in the net are going to do something and STP will break down, either partitioning the net, or causing loops. You could have the Z80 monitor for the host going away, and either taking over the STP, or cleanly shutting the switch down. But Marvells real use case for the Z80 is for it to manage the switch, no DSA at all. Just a dumb unmanaged, so very simple managed switch. > But otherwise, I don't know whether there's anything really actionable > here. What the ocelot driver calls a CPU port is always a "port > towards the CPU running Linux and managing the switch", so the CPU > port is always local by definition, no matter whether the CPU is > connected over DMA or over Ethernet (aka NPI mode or not). Well, it got me confused, but i think i have it now. It is more about new people getting up to speed on the driver, especially if they have experience with other DSA drivers, and suddenly the CPU port can mean something different. Andrew