Hi Andrew,
Andrew Lunn <and...@lunn.ch> writes:
> On Fri, May 27, 2016 at 10:33:49AM -0400, Vivien Didelot wrote:
>> Hi Andrew,
>>
>> Andrew Lunn <and...@lunn.ch> writes:
>>
>> > -static void dsa_switch_destroy(struct dsa_switch *ds)
>> > +void dsa_cpu_dsa_destroy(struct device_node *port_dn)
>> > {
>> > - struct device_node *port_dn;
>> > struct phy_device *phydev;
>> > +
>> > + if (of_phy_is_fixed_link(port_dn)) {
>> > + phydev = of_phy_find_device(port_dn);
>> > + if (phydev) {
>> > + phy_device_free(phydev);
>> > + fixed_phy_unregister(phydev);
>> > + }
>> > + }
>> > +}
>> > +
>> > +static void dsa_switch_destroy(struct dsa_switch *ds)
>> > +{
>> > int port;
>> >
>> > #ifdef CONFIG_NET_DSA_HWMON
>> > @@ -445,17 +467,11 @@ static void dsa_switch_destroy(struct dsa_switch *ds)
>> > dsa_slave_destroy(ds->ports[port].netdev);
>> > }
>> >
>> > - /* Remove any fixed link PHYs */
>> > + /* Disable configuration of the CPU and DSA ports */
>> > for (port = 0; port < DSA_MAX_PORTS; port++) {
>> > - port_dn = ds->ports[port].dn;
>> > - if (of_phy_is_fixed_link(port_dn)) {
>> > - phydev = of_phy_find_device(port_dn);
>> > - if (phydev) {
>> > - phy_device_free(phydev);
>> > - of_node_put(port_dn);
>>
>> Why does dsa_cpu_dsa_destroy drop that of_node_put call?
>
> The of node reference counting is broken. The DT maintainers actually
> say not to care, the whole reference counting scheme is broken. Which
> is a bit sad really. There was a discussion about this a couple of
> months ago.
>
> Anyway, the reference is taken in dsa_of_probe() as part of the
> or_each_available_child_of_node(child, port). This reference has
> nothing to do with the port being a fixed link or not. So freeing it
> here is inappropriate. The correct place to free it would probably be
> in dsa_of_remove.
OK, good to know. Can you split that in its own patch (prefered), or at
least document that in the commit message?
>> > - fixed_phy_unregister(phydev);
>> > - }
>> > - }
>> > + if ((dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port)))
>> > + continue;
>>
>> Why do we skip DSA and CPU ports here? The previous code didn't.
>>
>> > + dsa_cpu_dsa_destroy(ds->ports[port].dn);
>
> They are now destroyed by the newly added dsa_cpu_dsa_destroy(). I'm
> making the code more symmetrical and easier to re-use. The inverse of
> this function is dsa_switch_setup_one() and it also uses a helper
> function to setup the dsa and cpu ports, dsa_cpu_dsa_setups().
But dsa_cpu_dsa_destroy() is not called here. Shouldn't we drop (like
before) or at least invert the condition above?
Thanks,
Vivien
