[PATCH v2 1/2] net: mdio: fix owner field for mdio buses registered using device-tree

[Florian Fainelli]

From: Maxime Bizon <mbizon@xxxxxxxxxx>

Bus ownership is wrong when using of_mdiobus_register() to register an mdio
bus. That function is not inline, so when it calls mdiobus_register() the wrong
THIS_MODULE value is captured.

Signed-off-by: Maxime Bizon <mbizon@xxxxxxxxxx>
Fixes: 90eff9096c01 ("net: phy: Allow splitting MDIO bus/device support from PHYs")
[florian: fix kdoc, added Fixes tag]
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
 drivers/net/mdio/of_mdio.c    | 12 +++++++-----
 drivers/net/phy/mdio_devres.c | 11 ++++++-----
 include/linux/of_mdio.h       | 22 +++++++++++++++++++---
 3 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/drivers/net/mdio/of_mdio.c b/drivers/net/mdio/of_mdio.c
index 510822d6d0d9..1e46e39f5f46 100644
--- a/drivers/net/mdio/of_mdio.c
+++ b/drivers/net/mdio/of_mdio.c
@@ -139,21 +139,23 @@ bool of_mdiobus_child_is_phy(struct device_node *child)
 EXPORT_SYMBOL(of_mdiobus_child_is_phy);
 
 /**
- * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
+ * __of_mdiobus_register - Register mii_bus and create PHYs from the device tree
  * @mdio: pointer to mii_bus structure
  * @np: pointer to device_node of MDIO bus.
+ * @owner: module owning the @mdio object.
  *
  * This function registers the mii_bus structure and registers a phy_device
  * for each child node of @np.
  */
-int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
+int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
+			  struct module *owner)
 {
 	struct device_node *child;
 	bool scanphys = false;
 	int addr, rc;
 
 	if (!np)
-		return mdiobus_register(mdio);
+		return __mdiobus_register(mdio, owner);
 
 	/* Do not continue if the node is disabled */
 	if (!of_device_is_available(np))
@@ -172,7 +174,7 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 	of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us);
 
 	/* Register the MDIO bus */
-	rc = mdiobus_register(mdio);
+	rc = __mdiobus_register(mdio, owner);
 	if (rc)
 		return rc;
 
@@ -236,7 +238,7 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 	mdiobus_unregister(mdio);
 	return rc;
 }
-EXPORT_SYMBOL(of_mdiobus_register);
+EXPORT_SYMBOL(__of_mdiobus_register);
 
 /**
  * of_mdio_find_device - Given a device tree node, find the mdio_device
diff --git a/drivers/net/phy/mdio_devres.c b/drivers/net/phy/mdio_devres.c
index b560e99695df..69b829e6ab35 100644
--- a/drivers/net/phy/mdio_devres.c
+++ b/drivers/net/phy/mdio_devres.c
@@ -98,13 +98,14 @@ EXPORT_SYMBOL(__devm_mdiobus_register);
 
 #if IS_ENABLED(CONFIG_OF_MDIO)
 /**
- * devm_of_mdiobus_register - Resource managed variant of of_mdiobus_register()
+ * __devm_of_mdiobus_register - Resource managed variant of of_mdiobus_register()
  * @dev:	Device to register mii_bus for
  * @mdio:	MII bus structure to register
  * @np:		Device node to parse
+ * @owner:	Owning module
  */
-int devm_of_mdiobus_register(struct device *dev, struct mii_bus *mdio,
-			     struct device_node *np)
+int __devm_of_mdiobus_register(struct device *dev, struct mii_bus *mdio,
+			       struct device_node *np, struct module *owner)
 {
 	struct mdiobus_devres *dr;
 	int ret;
@@ -117,7 +118,7 @@ int devm_of_mdiobus_register(struct device *dev, struct mii_bus *mdio,
 	if (!dr)
 		return -ENOMEM;
 
-	ret = of_mdiobus_register(mdio, np);
+	ret = __of_mdiobus_register(mdio, np, owner);
 	if (ret) {
 		devres_free(dr);
 		return ret;
@@ -127,7 +128,7 @@ int devm_of_mdiobus_register(struct device *dev, struct mii_bus *mdio,
 	devres_add(dev, dr);
 	return 0;
 }
-EXPORT_SYMBOL(devm_of_mdiobus_register);
+EXPORT_SYMBOL(__devm_of_mdiobus_register);
 #endif /* CONFIG_OF_MDIO */
 
 MODULE_LICENSE("GPL");
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index da633d34ab86..8a52ef2e6fa6 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -14,9 +14,25 @@
 
 #if IS_ENABLED(CONFIG_OF_MDIO)
 bool of_mdiobus_child_is_phy(struct device_node *child);
-int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np);
-int devm_of_mdiobus_register(struct device *dev, struct mii_bus *mdio,
-			     struct device_node *np);
+int __of_mdiobus_register(struct mii_bus *mdio, struct device_node *np,
+			  struct module *owner);
+
+static inline int of_mdiobus_register(struct mii_bus *mdio,
+				      struct device_node *np)
+{
+	return __of_mdiobus_register(mdio, np, THIS_MODULE);
+}
+
+int __devm_of_mdiobus_register(struct device *dev, struct mii_bus *mdio,
+			       struct device_node *np, struct module *owner);
+
+static inline int devm_of_mdiobus_register(struct device *dev,
+					   struct mii_bus *mdio,
+					   struct device_node *np)
+{
+	return __devm_of_mdiobus_register(dev, mdio, np, THIS_MODULE);
+}
+
 struct mdio_device *of_mdio_find_device(struct device_node *np);
 struct phy_device *of_phy_find_device(struct device_node *phy_np);
 struct phy_device *
-- 
2.34.1