From cff9c565e65f3622e8dc1dcc21c1520a083dff35 Mon Sep 17 00:00:00 2001 From: Luiz Angelo Daros de Luca Date: Wed, 20 Dec 2023 01:52:29 -0300 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- drivers/net/mdio/of_mdio.c | 12 +++++++++++- drivers/net/phy/mdio_bus.c | 3 +++ include/linux/phy.h | 3 +++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/net/mdio/of_mdio.c b/drivers/net/mdio/of_mdio.c index 64ebcb6d235c..9b6cab6154e0 100644 --- a/drivers/net/mdio/of_mdio.c +++ b/drivers/net/mdio/of_mdio.c @@ -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); diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 6cf73c15635b..4a30757c4ff8 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -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); diff --git a/include/linux/phy.h b/include/linux/phy.h index e9e85d347587..ede891776d8b 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -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)