Re: [PATCH net-next 06/12] net: dsa: rzn1-a5psw: add Renesas RZ/N1 advanced 5 port switch driver

From: "Clément Léger" <clement.leger@bootlin.com>
To: Vladimir Oltean <olteanv@gmail.com>
Cc: "Andrew Lunn" <andrew@lunn.ch>,
	"Vivien Didelot" <vivien.didelot@gmail.com>,
	"Florian Fainelli" <f.fainelli@gmail.com>,
	"David S . Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Paolo Abeni" <pabeni@redhat.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Geert Uytterhoeven" <geert+renesas@glider.be>,
	"Magnus Damm" <magnus.damm@gmail.com>,
	"Heiner Kallweit" <hkallweit1@gmail.com>,
	"Russell King" <linux@armlinux.org.uk>,
	"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>,
	"Herve Codina" <herve.codina@bootlin.com>,
	"Miquèl Raynal" <miquel.raynal@bootlin.com>,
	"Milan Stevanovic" <milan.stevanovic@se.com>,
	"Jimmy Lalande" <jimmy.lalande@se.com>,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
	linux-renesas-soc@vger.kernel.org, netdev@vger.kernel.org,
	"Jean-Pierre Geslin" <jean-pierre.geslin@non.se.com>,
	"Phil Edworthy" <phil.edworthy@renesas.com>
Subject: Re: [PATCH net-next 06/12] net: dsa: rzn1-a5psw: add Renesas RZ/N1 advanced 5 port switch driver
Date: Fri, 15 Apr 2022 14:31:20 +0200	[thread overview]
Message-ID: <20220415143120.4c406ff9@fixe.home> (raw)
In-Reply-To: <20220415110524.4lhue7gcwqlhk2iv@skbuf>

Le Fri, 15 Apr 2022 14:05:24 +0300,
Vladimir Oltean <olteanv@gmail.com> a écrit :

> On Fri, Apr 15, 2022 at 01:55:03PM +0300, Vladimir Oltean wrote:
> > > > The selftests don't cover nearly enough, but just to make sure that they
> > > > pass for your switch, when you use 2 switch ports as h1 and h2 (hosts),
> > > > and 2 ports as swp1 and swp2? There's surprisingly little that you do on
> > > > .port_bridge_join, I need to study the code more.  
> > > 
> > > Port isolation is handled by using a pattern matcher which is enabled
> > > for each port at setup. If set, the port packet will only be forwarded
> > > to the CPU port. When bridging is needed, the pattern matching is
> > > disabled and thus, the packets are forwarded between all the ports that
> > > are enabled in the bridge.  
> > 
> > Is there some public documentation for this pattern matcher?  
> 
> Again, I realize I haven't made it clear what concerns me here.
> On ->port_bridge_join() and ->port_bridge_leave(), the "bridge" is given
> to you as argument. 2 ports may join br0, and 2 ports may join br1.
> You disregard the "bridge" argument. So you enable forwarding between
> br0 and br1. What I'd like to see is what the hardware can do in terms
> of this "pattern matching", to improve on this situation.

Yes, you are right, the driver currently won't support 2 differents
bridges. Either I add checks to support explicitely only one, or I add
support for multiple bridges. This would probably requires to use VLAN
internally to separate trafic.

-- 
Clément Léger,
Embedded Linux and Kernel engineer at Bootlin
https://bootlin.com