of: of_mdio: Ensure mdio device is a PHY

of_phy_find_device() is used to find the phy device associated with a
device node. It is expected the node is for a PHY device, but in fact
it could of been probed as a generic MDIO device. Ensure the device is
a PHY before returning it.

Fixes: a9049e0c513c ("mdio: Add support for mdio drivers.")
Reported-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Reported-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 86829f8..b5aa004 100644 (file)
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -256,11 +256,19 @@ static int of_phy_match(struct device *dev, void *phy_np)
 struct phy_device *of_phy_find_device(struct device_node *phy_np)
 {
        struct device *d;
+       struct mdio_device *mdiodev;
+
        if (!phy_np)
                return NULL;
 
        d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
-       return d ? to_phy_device(d) : NULL;
+       if (d) {
+               mdiodev = to_mdio_device(d);
+               if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY)
+                       return to_phy_device(d);
+       }
+
+       return NULL;
 }
 EXPORT_SYMBOL(of_phy_find_device);