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.
> > - 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().
Andrew
