From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: DSA vs. SWTICHDEV ? Date: Wed, 30 Nov 2016 21:43:34 +0100 Message-ID: <20161130204334.GC1864@nanopsycho.orion> References: <1480495831.3563.135.camel@infinera.com> <20161130135257.GC18716@lunn.ch> <1480516241.3563.142.camel@infinera.com> <20161130152503.GE21645@lunn.ch> <1480523716.3563.144.camel@infinera.com> <20161130165500.GH21645@lunn.ch> <1480527852.3563.146.camel@infinera.com> <20161130180927.GK21645@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Joakim Tjernlund , Florian Fainelli , "netdev@vger.kernel.org" To: Andrew Lunn Return-path: Received: from mail-wj0-f174.google.com ([209.85.210.174]:35576 "EHLO mail-wj0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754688AbcK3Unx (ORCPT ); Wed, 30 Nov 2016 15:43:53 -0500 Received: by mail-wj0-f174.google.com with SMTP id v7so186515569wjy.2 for ; Wed, 30 Nov 2016 12:43:37 -0800 (PST) Content-Disposition: inline In-Reply-To: <20161130180927.GK21645@lunn.ch> Sender: netdev-owner@vger.kernel.org List-ID: Wed, Nov 30, 2016 at 07:09:27PM CET, andrew@lunn.ch wrote: >> Something like that. I need to run routing protocols on the switch I/Fs and egress >> pkgs on selected switch I/Fs bypassing ARP, just like DSA does with its vendor >> tags. > >Does the switch have an equivalent tagging protocol? If you are >building a tree of switches you need something like this for frames >going from the host via intermediate switches and out a specific port >on a remote switch. > >> We might have a tree as well so now I really wonder: Given we write a >> proper switchdev driver, can it support switchtrees without touching >> switchdev infra structure? > >Jiri Pirko is probably the best person to ask about >this. DSA hides the knowledge that there is multiple switches. To >switchdev, a tree of switches looks like one switch. This is not >because of switchdev, it is just the existing DSA code worked when >switchdev came along. Looks like the hw is DSA-ish. If I'm not mistaken about that, should be handled as a part of DSA. > > If not I guess we will attach a physical >> eth I/F to the switch and use both DSA and switchdev to support both trees >> and HW offload. > >This only works if the switch has the necessary tagging protocol to >pass through multiple switches. > >> We have on an existing board with a BCM ROBO switch with lots of ports(>24), >> managed over SPI. Looking at BCM DSA tag code it looks like it only supports >> some 8 ports or so. I still have to find out if this is a limitation in BCM tagging >> protocol or if just not impl. in DSA yet. > >Hi Florian, care to comment? > >As far as i understand, the tag used for SF2 and B53 does not support >a tree of switches. But the big ROBO switches might have a different >tagging protocol. > > Andrew