Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 4 Mar 2022 00:28:48 +0200
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Tobias Waldekranz <tobias@waldekranz.com>
Cc:     davem@davemloft.net, kuba@kernel.org, Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>,
        Ivan Vecera <ivecera@redhat.com>,
        Roopa Prabhu <roopa@nvidia.com>,
        Nikolay Aleksandrov <razor@blackwall.org>,
        Russell King <linux@armlinux.org.uk>,
        Petr Machata <petrm@nvidia.com>,
        Cooper Lees <me@cooperlees.com>,
        Ido Schimmel <idosch@nvidia.com>,
        Matt Johnston <matt@codeconstruct.com.au>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        bridge@lists.linux-foundation.org
Subject: Re: [PATCH v2 net-next 01/10] net: bridge: mst: Multiple Spanning
 Tree (MST) mode
Message-ID: <20220303222848.4e2s2zrbzfckmiqw@skbuf>
References: <20220301100321.951175-1-tobias@waldekranz.com>
 <20220301100321.951175-2-tobias@waldekranz.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220301100321.951175-2-tobias@waldekranz.com>
Precedence: bulk

On Tue, Mar 01, 2022 at 11:03:12AM +0100, Tobias Waldekranz wrote:
> Allow the user to switch from the current per-VLAN STP mode to an MST
> mode.
> 
> Up to this point, per-VLAN STP states where always isolated from each
> other. This is in contrast to the MSTP standard (802.1Q-2018, Clause
> 13.5), where VLANs are grouped into MST instances (MSTIs), and the
> state is managed on a per-MSTI level, rather that at the per-VLAN
> level.
> 
> Perhaps due to the prevalence of the standard, many switching ASICs
> are built after the same model. Therefore, add a corresponding MST
> mode to the bridge, which we can later add offloading support for in a
> straight-forward way.
> 
> For now, all VLANs are fixed to MSTI 0, also called the Common
> Spanning Tree (CST). That is, all VLANs will follow the port-global
> state.
> 
> Upcoming changes will make this actually useful by allowing VLANs to
> be mapped to arbitrary MSTIs and allow individual MSTI states to be
> changed.
> 
> Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
> ---
> +void br_mst_vlan_set_state(struct net_bridge_port *p, struct net_bridge_vlan *v,
> +			   u8 state)

Function can be static.

> +{
> +	struct net_bridge_vlan_group *vg = nbp_vlan_group(p);
> +
> +	if (v->state == state)
> +		return;
> +
> +	br_vlan_set_state(v, state);
> +
> +	if (v->vid == vg->pvid)
> +		br_vlan_set_pvid_state(vg, state);
> +}