net: mdio: get/put device node during (un)registration

The __of_mdiobus_register() function was storing the device node in
dev.of_node without increasing its reference count. It implicitly relied
on the caller to maintain the allocated node until the mdiobus was
unregistered.

Now, __of_mdiobus_register() will acquire the node before assigning it,
and of_mdiobus_unregister_callback() will be called at the end of
mdio_unregister().

Drivers can now release the node immediately after MDIO registration.
Some of them are already doing that even before this patch.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Luiz Angelo Daros de Luca 2023-12-20 01:52:29 -03:00 committed by David S. Miller
parent 92de776d20
commit cff9c565e6
3 changed files with 17 additions and 1 deletions

View File

@ -139,6 +139,11 @@ bool of_mdiobus_child_is_phy(struct device_node *child)
}
EXPORT_SYMBOL(of_mdiobus_child_is_phy);
static void __of_mdiobus_unregister_callback(struct mii_bus *mdio)
{
of_node_put(mdio->dev.of_node);
}
/**
* __of_mdiobus_register - Register mii_bus and create PHYs from the device tree
* @mdio: pointer to mii_bus structure
@ -166,6 +171,8 @@ int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
* the device tree are populated after the bus has been registered */
mdio->phy_mask = ~0;
mdio->__unregister_callback = __of_mdiobus_unregister_callback;
of_node_get(np);
device_set_node(&mdio->dev, of_fwnode_handle(np));
/* Get bus level PHY reset GPIO details */
@ -177,7 +184,7 @@ int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
/* Register the MDIO bus */
rc = __mdiobus_register(mdio, owner);
if (rc)
return rc;
goto put_node;
/* Loop over the child nodes and register a phy_device for each phy */
for_each_available_child_of_node(np, child) {
@ -237,6 +244,9 @@ int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
unregister:
of_node_put(child);
mdiobus_unregister(mdio);
put_node:
of_node_put(np);
return rc;
}
EXPORT_SYMBOL(__of_mdiobus_register);

View File

@ -787,6 +787,9 @@ void mdiobus_unregister(struct mii_bus *bus)
gpiod_set_value_cansleep(bus->reset_gpiod, 1);
device_del(&bus->dev);
if (bus->__unregister_callback)
bus->__unregister_callback(bus);
}
EXPORT_SYMBOL(mdiobus_unregister);

View File

@ -434,6 +434,9 @@ struct mii_bus {
/** @shared: shared state across different PHYs */
struct phy_package_shared *shared[PHY_MAX_ADDR];
/** @__unregister_callback: called at the last step of unregistration */
void (*__unregister_callback)(struct mii_bus *bus);
};
#define to_mii_bus(d) container_of(d, struct mii_bus, dev)