Re: [PATCH net-next v5 2/3] net: dsa: rzn1-a5psw: add support for .port_bridge_flags

From: Vladimir Oltean <olteanv@gmail.com>
To: alexis.lothore@bootlin.com
Cc: "Clément Leger" <clement@clement-leger.fr>,
	"Andrew Lunn" <andrew@lunn.ch>,
	"Florian Fainelli" <f.fainelli@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	"Eric Dumazet" <edumazet@google.com>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Paolo Abeni" <pabeni@redhat.com>,
	linux-renesas-soc@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	"Miquel Raynal" <miquel.raynal@bootlin.com>,
	"Milan Stevanovic" <milan.stevanovic@se.com>,
	"Jimmy Lalande" <jimmy.lalande@se.com>,
	"Pascal Eberhard" <pascal.eberhard@se.com>,
	"Thomas Petazzoni" <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH net-next v5 2/3] net: dsa: rzn1-a5psw: add support for .port_bridge_flags
Date: Fri, 11 Aug 2023 13:03:07 +0300	[thread overview]
Message-ID: <20230811100307.ocqkijjj5f6hi3q2@skbuf> (raw)
In-Reply-To: <20230810093651.102509-3-alexis.lothore@bootlin.com>

Hi Alexis,

On Thu, Aug 10, 2023 at 11:36:50AM +0200, alexis.lothore@bootlin.com wrote:
> +	if (flags.mask & BR_FLOOD) {
> +		val = flags.val & BR_FLOOD ? BIT(port) : 0;
> +		a5psw_reg_rmw(a5psw, A5PSW_UCAST_DEF_MASK, BIT(port), val);
> +	}
> +
> +	if (flags.mask & BR_MCAST_FLOOD) {
> +		val = flags.val & BR_MCAST_FLOOD ? BIT(port) : 0;
> +		a5psw_reg_rmw(a5psw, A5PSW_MCAST_DEF_MASK, BIT(port), val);
> +	}
> +
> +	if (flags.mask & BR_BCAST_FLOOD) {
> +		val = flags.val & BR_BCAST_FLOOD ? BIT(port) : 0;
> +		a5psw_reg_rmw(a5psw, A5PSW_BCAST_DEF_MASK, BIT(port), val);
> +	}

These 3 port masks will only do what you expect while the bridge has
vlan_filtering=0, correct? When vlan_filtering=1, packets classified to
a VLAN which don't hit any FDB entry will be always flooded to all ports
in that VLAN, correct?

Maybe you could restrict transitions to flooding disabled on ports with
vlan_filtering 1, and restrict transitions to vlan_filtering 1 on ports
with flooding disabled. Or at least add some comments about the
limitations. I wouldn't want subtle incompatibilities between the
hardware design and Linux' expectations to go under the radar like this.