On Tue, Mar 14, 2023 at 05:36:50PM +0100, Clément Léger wrote:
> +static int a5psw_port_pre_bridge_flags(struct dsa_switch *ds, int port,
> + struct switchdev_brport_flags flags,
> + struct netlink_ext_ack *extack)
> +{
> + if (flags.mask & ~(BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD |
> + BR_BCAST_FLOOD))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static int
> +a5psw_port_bridge_flags(struct dsa_switch *ds, int port,
> + struct switchdev_brport_flags flags,
> + struct netlink_ext_ack *extack)
> +{
> + struct a5psw *a5psw = ds->priv;
> + u32 val;
> +
> + if (flags.mask & BR_LEARNING) {
> + val = flags.val & BR_LEARNING ? 0 : A5PSW_INPUT_LEARN_DIS(port);
> + a5psw_reg_rmw(a5psw, A5PSW_INPUT_LEARN,
> + A5PSW_INPUT_LEARN_DIS(port), val);
> + }
2 issues.
1: does this not get overwritten by a5psw_port_stp_state_set()?
2: What is the hardware default value for A5PSW_INPUT_LEARN? Please make
sure that standalone ports have learning disabled by default, when
the driver probes.
> +
> + 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);
> + }
Humm, there's a (huge) problem with this flooding mask.
a5psw_flooding_set_resolution() - called from a5psw_port_bridge_join()
and a5psw_port_bridge_leave() - touches the same registers as
a5psw_port_bridge_flags(). Which means that your bridge forwarding
domain controls are the same as your flooding controls.
Which is bad news, because
dsa_port_bridge_leave()
-> dsa_port_switchdev_unsync_attrs()
-> dsa_port_clear_brport_flags()
-> dsa_port_bridge_flags()
-> a5psw_port_bridge_flags()
enables flooding on the port after calling a5psw_port_bridge_leave().
So the port which has left a bridge is standalone, but it still forwards
packets to the other bridged ports!
You should be able to see that this is the case, if you put the ports
under a dummy bridge, then run tools/testing/selftests/drivers/net/dsa/no_forwarding.sh.
