From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH RFC 2/2] net: dsa: bcm_sf2: implement HW bridging operations Date: Thu, 19 Feb 2015 16:09:35 -0800 Message-ID: <20150220000935.GA30118@roeck-us.net> References: <1424201196-4901-1-git-send-email-f.fainelli@gmail.com> <1424201196-4901-3-git-send-email-f.fainelli@gmail.com> <54E54EF3.9020802@gmail.com> <20150219055953.GA14247@roeck-us.net> <54E61CFB.3010109@gmail.com> <20150219174640.GA6897@roeck-us.net> <54E676DD.9090003@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, davem@davemloft.net, vivien.didelot@savoirfairelinux.com, jerome.oufella@savoirfairelinux.com, andrew@lunn.ch, cphealy@gmail.com To: Florian Fainelli Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:44123 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752018AbbBTAJk (ORCPT ); Thu, 19 Feb 2015 19:09:40 -0500 Received: from mailnull by bh-25.webhostbox.net with sa-checked (Exim 4.82) (envelope-from ) id 1YObA3-000Oqo-Av for netdev@vger.kernel.org; Fri, 20 Feb 2015 00:09:39 +0000 Content-Disposition: inline In-Reply-To: <54E676DD.9090003@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Feb 19, 2015 at 03:50:53PM -0800, Florian Fainelli wrote: > On 19/02/15 09:46, Guenter Roeck wrote: > > On Thu, Feb 19, 2015 at 09:27:23AM -0800, Florian Fainelli wrote: > >> On 18/02/15 21:59, Guenter Roeck wrote: > >>> On Wed, Feb 18, 2015 at 06:48:19PM -0800, Florian Fainelli wrote: > >>>> On 17/02/15 11:26, Florian Fainelli wrote: > >>>>> Update the Broadcom Starfighter 2 switch driver to implement the > >>>>> join/leave/stp_update callbacks required for basic hardware bridging > >>>>> support. > >>>>> > >>>>> There is not much to be done at the driver level but translating the > >>>>> STP state from Linux to their HW values. > >>>>> > >>>>> Joining a bridge means that the joining port and the other port members > >>>>> need to be in the same VLAN membership as the CPU, while leaving the > >>>>> bridge puts the port back into a separate VLAN membership with only the > >>>>> CPU. > >>>> > >>>> I found a couple additional issues while testing: > >>>> > >>>> - manipulating UP/DOWN state of interfaces that are part of a bridge > >>>> would not restore their bridge membership > >>>> > >>>> - removing an interface from a bridge and bringing it back up would > >>>> leave it in blocked state > >>>> > >>> Is this a problem with your implementation for sf2 or a generic problem > >>> with the first patch, such as some missing state transitions ? > >> > >> This is more of a side effect of having HW (an Ethernet switch) that can > >> really block a given port, based on last night's discussion with Roopa, > >> we can either fix this at the DSA level (in our case) or better fix this > >> at the bridge layer, I will propose a fix for this shortly. > >> > >>> > >>> For sf2, you might have to set the port state as well as the bridge > >>> association in the port_setup function. That is of course just a > >>> wild guess. > >> > >> Right, that's what I ended up doing. Thanks! > > > > Great. > > > > Another question: How do you handle flushing the forwarding database ? > > > > My current code for mv88e6352 flushes the forwarding database for a bridge > > group if the port association for that group changes (whenever a port joins > > or leaves a group, or whenever the state of a port in a group changes). > > There is, however, another situation where the forwarding database may > > have to be flushed - essentially on each topology change. > > > > How do you handle this situation ? Is it a real problem or do I just > > imagine that it is ? > > This is a real problem, for once I was working under the assumption that > the SF2 hardware was doing an automatic FDB flushing, but after > re-reading the documentation, this is not the case. My lab network does > not have many stations and I certainly did not catch that case. The rocker code implements the fdb flush operation pretty much the same way I do, so I seem to be doing something right. Not sure yet what to do about setting the fdb aging time. I don't see a mechanism to do that. No idea how important that is. I think we'll also need support for ndo_vlan_rx_add_vid, ndo_vlan_rx_kill_vid, ndo_fdb_add, ndo_fdb_del, and ndo_fdb_dump. Have you thought about those ? Thanks, Guenter