Hi Florian,
Florian Fainelli <f.faine...@gmail.com> writes:
>> Also I do not think that it is a good thing that a DSA driver play much
>> in dsa_port structures (they are ideally DSA core only specific data).
>> They only seem to need the master interface, so what I see is:
>>
>> static inline struct net_device *dsa_get_master(struct dsa_switch *ds,
>> int port)
>> {
>> struct dsa_port *dp = &ds->ports[port];
>>
>> if (!dsa_is_cpu_port(ds, port))
>> dp = dp->cpu_dp;
>>
>> return dp->netdev;
>> }
>
> The port parameter is kind of pointless, that is what I was trying to
> say, see below.
>
> MT7530_CPU_PORT = 6 and there is a define above for 7 ports, so it is
> presumably the default CPU port that the switch uses. With Broadcom
> switches you could have port 5, 7 or 8 as CPU ports but 8 is still the
> default for most 9-ports capable switches.
>
>> Now let's think that you can have several CPU ports (as with mv88e6xxx).
>> I think it is the driver responsibility to iterate over CPU capable
>> ports and inspect the master devices if they need to, instead of having
>> DSA core return an arbitrary one (which might be the wrong one.)
>
> OK, then are you okay if I do this in mt7530.c instead:
>
> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
> index 1e46418a3b74..d5b63958dd85 100644
> --- a/drivers/net/dsa/mt7530.c
> +++ b/drivers/net/dsa/mt7530.c
> @@ -907,17 +907,26 @@ static int
> mt7530_setup(struct dsa_switch *ds)
> {
> struct mt7530_priv *priv = ds->priv;
> + struct dsa_port *port;
> int ret, i;
> u32 id, val;
> struct device_node *dn;
> struct mt7530_dummy_poll p;
>
> - /* The parent node of cpu_dp->netdev which holds the common system
> - * controller also is the container for two GMACs nodes representing
> - * as two netdev instances.
> - */
> - dn = ds->dst->cpu_dp->netdev->dev.of_node->parent;
> - priv->ethernet = syscon_node_to_regmap(dn);
> + for (i = 0; i < ds->num_ports; i++) {
> + port = &ds->ports[i];
> + /* The parent node of cpu_dp->netdev which holds the common
> + * system controller also is the container for two GMACs
> nodes
> + * representing as two netdev instances.
> + */
> + if (dsa_is_cpu_port(ds, i)) {
> + dn = port->netdev->dev.of_node->parent;
> + if (priv->ethernet)
> + return -EEXIST;
> + priv->ethernet = syscon_node_to_regmap(dn);
> + }
> + }
> +
> if (IS_ERR(priv->ethernet))
> return PTR_ERR(priv->ethernet);
I think it is the correct way to do this.
This was the reason why I suggested a dsa_get_master() alternative, even
though it is not necessary per-se, it was just to reduce boilerplate and
avoid exposing too much the dsa_port structures.
dsa_ds_get_cpu_dp() doesn't make much sense anymore, right? If there are
2 CPU ports in use, it is better that the driver iterates on them itself
as you did, instead of having DSA return the first one it knows about.
Thanks,
Vivien
