Commit cff9c565 authored by Luiz Angelo Daros de Luca's avatar Luiz Angelo Daros de Luca Committed by David S. Miller
Browse files

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: default avatarLuiz Angelo Daros de Luca <luizluca@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 92de776d

drivers/net/mdio/of_mdio.c

+11 −1
Original line number Diff line number Diff line
@@ -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);

drivers/net/phy/mdio_bus.c

+3 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/phy.h

+3 −0
Original line number Diff line number Diff line
@@ -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)