Re: [PATCH net-next 2/2] net: dsa: mt7530: add support for bridge port isolation

[Matthias Schiffer]

On 16/06/2024 08:52, Arınç ÜNAL wrote:
> On 15/06/2024 01:21, Matthias Schiffer wrote:
> > Remove a pair of ports from the port matrix when both ports have the
> > isolated flag set.
> >
> > Signed-off-by: Matthias Schiffer <mschiffer@xxxxxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/net/dsa/mt7530.c | 21 ++++++++++++++++++---
> >   drivers/net/dsa/mt7530.h |  1 +
> >   2 files changed, 19 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
> > index ecacaefdd694..44939379aba8 100644
> > --- a/drivers/net/dsa/mt7530.c
> > +++ b/drivers/net/dsa/mt7530.c
> > @@ -1303,7 +1303,8 @@ mt7530_stp_state_set(struct dsa_switch *ds, int 
> > port, u8 state)
> >   }
> >   static void mt7530_update_port_member(struct mt7530_priv *priv, int port,
> > -                      const struct net_device *bridge_dev, bool join)
> > +                      const struct net_device *bridge_dev,
> > +                      bool join)
>
> Run git clang-format on this patch as well please.

Oops, will do.


> >       __must_hold(&priv->reg_mutex)
> >   {
> >       struct dsa_port *dp = dsa_to_port(priv->ds, port), *other_dp;
> > @@ -1311,6 +1312,7 @@ static void mt7530_update_port_member(struct 
> > mt7530_priv *priv, int port,
> >       struct dsa_port *cpu_dp = dp->cpu_dp;
> >       u32 port_bitmap = BIT(cpu_dp->index);
> >       int other_port;
> > +    bool isolated;
> >       dsa_switch_for_each_user_port(other_dp, priv->ds) {
> >           other_port = other_dp->index;
> > @@ -1327,7 +1329,9 @@ static void mt7530_update_port_member(struct 
> > mt7530_priv *priv, int port,
> >           if (!dsa_port_offloads_bridge_dev(other_dp, bridge_dev))
> >               continue;
> > -        if (join) {
> > +        isolated = p->isolated && other_p->isolated;
> > +
> > +        if (join && !isolated) {
> >               other_p->pm |= PCR_MATRIX(BIT(port));
> >               port_bitmap |= BIT(other_port);
> >           } else {
>
> Why must other_p->isolated be true as well? If I understand correctly, when
> a user port is isolated, non isolated ports can't communicate with it
> whilst the CPU port can. If I were to isolate a port which is the only
> isolated one at the moment, the isolated flag would not be true. Therefore,
> the isolated port would not be removed from the port matrix of other user
> ports. Why not only check for p->isolated?

As far as I can tell, the rules are:

- non-isolated ports can communicate with every port
- isolated ports can't communicate with other isolated ports
- communication is symmetric

You'll find that the logic works the same for non-offloaded bridge 
forwarding (see should_deliver() in net/bridge/br_forward.c and 
br_skb_isolated() in net/bridge/br_private.h).

Matthias

Attachment: OpenPGP_signature.asc
Description: OpenPGP digital signature