From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH net-next 0/4] net: dsa: mv88e6xxx: fix hardware bridging Date: Wed, 14 Oct 2015 20:16:27 -0700 Message-ID: <561F1A8B.1040904@roeck-us.net> References: <1444601318-20561-1-git-send-email-vivien.didelot@savoirfairelinux.com> <20151014224617.GA10146@lunn.ch> <20151015012854.GA10868@ketchup.lan> <20151015025250.GA12436@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@savoirfairelinux.com, "David S. Miller" , Florian Fainelli , Neil Armstrong To: Andrew Lunn , Vivien Didelot Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:53733 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751103AbbJODQa (ORCPT ); Wed, 14 Oct 2015 23:16:30 -0400 In-Reply-To: <20151015025250.GA12436@lunn.ch> Sender: netdev-owner@vger.kernel.org List-ID: On 10/14/2015 07:52 PM, Andrew Lunn wrote: > On Wed, Oct 14, 2015 at 09:28:55PM -0400, Vivien Didelot wrote: >> On Oct. Thursday 15 (42) 12:46 AM, Andrew Lunn wrote: >>> On Sun, Oct 11, 2015 at 06:08:34PM -0400, Vivien Didelot wrote: >>>> DSA and its drivers currently hook the NETDEV_CHANGEUPPER net_device event in >>>> order to configure the VLAN map of every port. >>>> >>>> This VLAN map is a feature of these switch chips to hardcode and restrict which >>>> output ports a given input port can egress frames to. >>>> >>>> A Linux bridge is a simple untagged VLAN propagated by the bridge code itself. >>>> With a proper 802.1Q support, a driver does not need this hook anymore, and >>>> will simply program the related VLAN object. >>>> >>>> This patchset improves the hardware bridging code in the mv88e6xxx driver with >>>> a strict 802.1Q mode. >>> >>> Hi Vivien >>> >>> I just tested this as part of net-next/master, and found a problem.... >>> >>> If i do: >>> >>> ip link set lan0 up >>> ip addr add 192.168.10.2/24 dev lan0 >>> >>> It will not ping. Looking in sys/kernel/debug/dsa0/stats i see >>> broadcast packets, probably ARP, being received at the port. >>> But they are not being forwarded out the CPU port. >>> >>> If however i do >>> >>> brctl addbr br0 >>> brctl addif br0 lan0 >>> ip addr add 192.168.10.2/24 dev br0 >>> ip link set br0 up >>> >>> i can ping. >>> >>> So it looks like we are too restrictive by default. You should be able >>> to use interfaces as they are, without a bridge. >> >> Correct, if the ports are not in a VLAN by default, they cannot talk. > > Hi Vivien > > This is a regression. Ports of the switch should work like normal > Linux interfaces. And up until now, they did. This patchset changed > that. > > As Florian pointed out, these interfaces are separated from each > other. So you need something like a bridge per port by default, which > then gets removed and replaced when a port is added to a Linux bridge. > > We also need to take care of VLANs. When the port is not a member of a > linux bridge, i expect all VLAN tagged frames to be received, as well > as untagged frames. This is normal Linux behaviour. But i never got > around to testing this with DSA. > There was a reason for the original code. I had wondered how it is now supposed to work. Guess this exchange explains it. Looking forward to see how it is going to be fixed, and too bad I don't have time to be more involved. Guenter