From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH RFC 2/2] net: dsa: bcm_sf2: implement HW bridging operations Date: Thu, 19 Feb 2015 18:03:01 -0800 Message-ID: <54E695D5.6080208@gmail.com> 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> <20150220000935.GA30118@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, davem@davemloft.net, vivien.didelot@savoirfairelinux.com, jerome.oufella@savoirfairelinux.com, andrew@lunn.ch, cphealy@gmail.com, Scott Feldman , Jiri Pirko To: Guenter Roeck Return-path: Received: from mail-pa0-f43.google.com ([209.85.220.43]:40238 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752711AbbBTCDP (ORCPT ); Thu, 19 Feb 2015 21:03:15 -0500 Received: by paceu11 with SMTP id eu11so4223853pac.7 for ; Thu, 19 Feb 2015 18:03:14 -0800 (PST) In-Reply-To: <20150220000935.GA30118@roeck-us.net> Sender: netdev-owner@vger.kernel.org List-ID: On 19/02/15 16:09, Guenter Roeck wrote: > 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 ? Yes, we will need those as well, although for now, I think we might just be able to get basic HW bridging to work with the current patches + driver specific FDB flushing, what do you think? The only part thing that I cannot really map to HW switches today is that the ndo_vlan_rx_add_vid() does not specify whether the VLAN id you are adding is tagged or untagged (aka native). You can configure that using the "bridge" sub-command from iproute2, but I am not sure how this translates in terms of programming the hardware with the tagged/untagged bit yet. Maybe we should update ndo_vlan_rx_add_vid() to allow for a tag bit to specified? -- Florian