Re: [net-next PATCH 2/3] net: dsa: qca8k: make learning configurable and keep off if standalone

[Simon Horman]

On Mon, Jul 24, 2023 at 05:30:57AM +0200, Christian Marangi wrote:
> Address learning should initially be turned off by the driver for port
> operation in standalone mode, then the DSA core handles changes to it
> via ds->ops->port_bridge_flags().
> 
> Currently this is not the case for qca8k where learning is enabled
> unconditionally in qca8k_setup for every user port.
> 
> Handle ports configured in standalone mode by making the learning
> configurable and not enabling it by default.
> 
> Implement .port_pre_bridge_flags and .port_bridge_flags dsa ops to
> enable learning for bridge that request it and tweak
> .port_stp_state_set to correctly disable learning when port is
> configured in standalone mode.
> 
> Signed-off-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
> diff --git a/drivers/net/dsa/qca/qca8k-8xxx.c b/drivers/net/dsa/qca/qca8k-8xxx.c

...

> @@ -1978,6 +1977,8 @@ static const struct dsa_switch_ops qca8k_switch_ops = {
>  	.port_change_mtu	= qca8k_port_change_mtu,
>  	.port_max_mtu		= qca8k_port_max_mtu,
>  	.port_stp_state_set	= qca8k_port_stp_state_set,
> +	.port_pre_bridge_flags	= qca8k_port_pre_bridge_flags,
> +	.port_bridge_flags	= qca8k_port_bridge_flags,
>  	.port_bridge_join	= qca8k_port_bridge_join,
>  	.port_bridge_leave	= qca8k_port_bridge_leave,
>  	.port_fast_age		= qca8k_port_fast_age,
> diff --git a/drivers/net/dsa/qca/qca8k-common.c b/drivers/net/dsa/qca/qca8k-common.c

...

> @@ -591,6 +611,30 @@ void qca8k_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
>  
>  	qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
>  		  QCA8K_PORT_LOOKUP_STATE_MASK, stp_state);
> +
> +	qca8k_port_configure_learning(ds, port, learning);
> +}
> +
> +int qca8k_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)
> +		return -EINVAL;

If I am reading things right then some implementation of this callback
return -EINVAL when they see unexpected flags. And some seem not to
- possibly because all flags are expected.

So I'm slightly unsure if this is correct or not.

> +
> +	return 0;
> +}

...