net: fix circular dependency in of_mdio code

Commit 86f6cf4127 (net: of_mdio: add of_mdiobus_link_phydev()) introduced a
circular dependency between libphy and of_mdio.

depmod: ERROR: <modroot>/kernel/drivers/net/phy/libphy.ko in
dependency cycle!
depmod: ERROR: <modroot>/kernel/drivers/of/of_mdio.ko in dependency cycle!

The problem is that of_mdio.c references &mdio_bus_type and libphy now
references of_mdiobus_link_phydev.

Fix this by not exporting of_mdiobus_link_phydev() from of_mdio.ko.
Make it a static function in mdio_bus.c instead.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Reported-by: Jeff Mahoney <jeffm@suse.com>
Fixes: 86f6cf4127 (net: of_mdio: add of_mdiobus_link_phydev())
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 2e58aa54484c..4eaadcfcb0fe 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -187,6 +187,50 @@ struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
 	return d ? to_mii_bus(d) : NULL;
 }
 EXPORT_SYMBOL(of_mdio_find_bus);
+
+/* Walk the list of subnodes of a mdio bus and look for a node that matches the
+ * phy's address with its 'reg' property. If found, set the of_node pointer for
+ * the phy. This allows auto-probed pyh devices to be supplied with information
+ * passed in via DT.
+ */
+static void of_mdiobus_link_phydev(struct mii_bus *mdio,
+				   struct phy_device *phydev)
+{
+	struct device *dev = &phydev->dev;
+	struct device_node *child;
+
+	if (dev->of_node || !mdio->dev.of_node)
+		return;
+
+	for_each_available_child_of_node(mdio->dev.of_node, child) {
+		int addr;
+		int ret;
+
+		ret = of_property_read_u32(child, "reg", &addr);
+		if (ret < 0) {
+			dev_err(dev, "%s has invalid PHY address\n",
+				child->full_name);
+			continue;
+		}
+
+		/* A PHY must have a reg property in the range [0-31] */
+		if (addr >= PHY_MAX_ADDR) {
+			dev_err(dev, "%s PHY address %i is too large\n",
+				child->full_name, addr);
+			continue;
+		}
+
+		if (addr == phydev->addr) {
+			dev->of_node = child;
+			return;
+		}
+	}
+}
+#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
+static inline void of_mdiobus_link_phydev(struct mii_bus *mdio,
+					  struct phy_device *phydev)
+{
+}
 #endif
 
 /**