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=-2.3 required=3.0 tests=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 4F3A1C2D0DB for ; Sun, 26 Jan 2020 13:22:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2BA6D20716 for ; Sun, 26 Jan 2020 13:22:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729332AbgAZNWQ (ORCPT ); Sun, 26 Jan 2020 08:22:16 -0500 Received: from esa6.microchip.iphmx.com ([216.71.154.253]:64656 "EHLO esa6.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726761AbgAZNWQ (ORCPT ); Sun, 26 Jan 2020 08:22:16 -0500 Received-SPF: Pass (esa6.microchip.iphmx.com: domain of Horatiu.Vultur@microchip.com designates 198.175.253.82 as permitted sender) identity=mailfrom; client-ip=198.175.253.82; receiver=esa6.microchip.iphmx.com; envelope-from="Horatiu.Vultur@microchip.com"; x-sender="Horatiu.Vultur@microchip.com"; x-conformance=spf_only; x-record-type="v=spf1"; x-record-text="v=spf1 mx a:ushub1.microchip.com a:smtpout.microchip.com -exists:%{i}.spf.microchip.iphmx.com include:servers.mcsv.net include:mktomail.com include:spf.protection.outlook.com ~all" Received-SPF: None (esa6.microchip.iphmx.com: no sender authenticity information available from domain of postmaster@email.microchip.com) identity=helo; client-ip=198.175.253.82; receiver=esa6.microchip.iphmx.com; envelope-from="Horatiu.Vultur@microchip.com"; x-sender="postmaster@email.microchip.com"; x-conformance=spf_only Authentication-Results: esa6.microchip.iphmx.com; dkim=none (message not signed) header.i=none; spf=Pass smtp.mailfrom=Horatiu.Vultur@microchip.com; spf=None smtp.helo=postmaster@email.microchip.com; dmarc=pass (p=none dis=none) d=microchip.com IronPort-SDR: Ko7PtFIUmKqu/uKzS/3kb6uOcIPdYFEtzg4pdcQduqsrc5irA1DX5GcbpFI7FYyZ4cNuocAFQG Xlm/63c6OyDIqOTIM8GeHzAWOpZF2cTSqe9InrQhN0vSWH3z3/Xg9I7gBqrT4/D/Gg6bkPaLVl zIBFVa2lSWt7sorP4/TUNpu9MB/wbDaWjjxJ4Q7NbcnzTXNzkyVZyN8JKgQ7cJKQanX343ka9t ba1mI+DzVe5OA1UcDDN/iVbD8QIZShhXQoH8b/5fX58hgGBtoHMVd5TB/d/Nl8IOitlcb2z+rA Lrg= X-IronPort-AV: E=Sophos;i="5.70,365,1574146800"; d="scan'208";a="121043" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa6.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 26 Jan 2020 06:22:15 -0700 Received: from chn-vm-ex01.mchp-main.com (10.10.85.143) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Sun, 26 Jan 2020 06:22:15 -0700 Received: from localhost (10.10.85.251) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server id 15.1.1713.5 via Frontend Transport; Sun, 26 Jan 2020 06:22:15 -0700 Date: Sun, 26 Jan 2020 14:22:13 +0100 From: Horatiu Vultur To: Andrew Lunn CC: , , , , , , , , , , , Subject: Re: [RFC net-next v3 06/10] net: bridge: mrp: switchdev: Extend switchdev API to offload MRP Message-ID: <20200126132213.fmxl5mgol5qauwym@soft-dev3.microsemi.net> References: <20200124161828.12206-1-horatiu.vultur@microchip.com> <20200124161828.12206-7-horatiu.vultur@microchip.com> <20200125163504.GF18311@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline In-Reply-To: <20200125163504.GF18311@lunn.ch> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The 01/25/2020 17:35, Andrew Lunn wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > > SWITCHDEV_OBJ_ID_RING_TEST_MRP: This is used when to start/stop sending > > MRP_Test frames on the mrp ring ports. This is called only on nodes that have > > the role Media Redundancy Manager. > > How do you handle the 'headless chicken' scenario? User space tells > the port to start sending MRP_Test frames. It then dies. The hardware > continues sending these messages, and the neighbours thinks everything > is O.K, but in reality the state machine is dead, and when the ring > breaks, the daemon is not there to fix it? > > And it is not just the daemon that could die. The kernel could opps or > deadlock, etc. > > For a robust design, it seems like SWITCHDEV_OBJ_ID_RING_TEST_MRP > should mean: start sending MRP_Test frames for the next X seconds, and > then stop. And the request is repeated every X-1 seconds. I totally missed this case, I will update this as you suggest. > > Andrew -- /Horatiu