Re: [PATCH net-next 09/13] net: dsa: lantiq_gswip: Forbid gswip_add_single_port_br on the CPU port

[Martin Schiller]

On 2024-06-07 13:26, Vladimir Oltean wrote:
> On Thu, Jun 06, 2024 at 10:52:30AM +0200, Martin Schiller wrote:
> > From: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> >
> > Calling gswip_add_single_port_br() with the CPU port would be a bug
> > because then only the CPU port could talk to itself. Add the CPU port 
> > to
> > the validation at the beginning of gswip_add_single_port_br().
> >
> > Signed-off-by: Martin Blumenstingl 
> > <martin.blumenstingl@xxxxxxxxxxxxxx>
> > ---
> >  drivers/net/dsa/lantiq_gswip.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/dsa/lantiq_gswip.c 
> > b/drivers/net/dsa/lantiq_gswip.c
> > index ee8296d5b901..d2195271ffe9 100644
> > --- a/drivers/net/dsa/lantiq_gswip.c
> > +++ b/drivers/net/dsa/lantiq_gswip.c
> > @@ -657,7 +657,7 @@ static int gswip_add_single_port_br(struct 
> > gswip_priv *priv, int port, bool add)
> >  	unsigned int max_ports = priv->hw_info->max_ports;
> >  	int err;
> >
> > -	if (port >= max_ports) {
> > +	if (port >= max_ports || dsa_is_cpu_port(priv->ds, port)) {
> >  		dev_err(priv->dev, "single port for %i supported\n", port);
> >  		return -EIO;
> >  	}
> > --
> > 2.39.2
>
> Isn't the new check effectively dead code?

As long as the dsa_switch_ops .port_bridge_join and .port_bridge_leave 
are not
executed for the cpu port, I agree with you.