net: dsa: mv88e6xxx: Unregister MDIO bus on error path

[ Upstream commit 3126aeec5313565bfa19e2dd8fd7e3c3390514cb ]

The MDIO busses need to be unregistered before they are freed,
otherwise BUG() is called. Add a call to the unregister code if the
registration fails, since we can have multiple busses, of which some
may correctly register before one fails. This requires moving the code
around a little.

Fixes: a3c53be55c95 ("net: dsa: mv88e6xxx: Support multiple MDIO busses")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 07704b372861c15edeb2f71fe8ccc2f0abeac6bc..eebda5ec9676be878d65977f49c58e35f42c02fb 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -2153,6 +2153,19 @@ static const struct of_device_id mv88e6xxx_mdio_external_match[] = {
        { },
 };
 
+static void mv88e6xxx_mdios_unregister(struct mv88e6xxx_chip *chip)
+
+{
+       struct mv88e6xxx_mdio_bus *mdio_bus;
+       struct mii_bus *bus;
+
+       list_for_each_entry(mdio_bus, &chip->mdios, list) {
+               bus = mdio_bus->bus;
+
+               mdiobus_unregister(bus);
+       }
+}
+
 static int mv88e6xxx_mdios_register(struct mv88e6xxx_chip *chip,
                                    struct device_node *np)
 {
@@ -2177,27 +2190,16 @@ static int mv88e6xxx_mdios_register(struct mv88e6xxx_chip *chip,
                match = of_match_node(mv88e6xxx_mdio_external_match, child);
                if (match) {
                        err = mv88e6xxx_mdio_register(chip, child, true);
-                       if (err)
+                       if (err) {
+                               mv88e6xxx_mdios_unregister(chip);
                                return err;
+                       }
                }
        }
 
        return 0;
 }
 
-static void mv88e6xxx_mdios_unregister(struct mv88e6xxx_chip *chip)
-
-{
-       struct mv88e6xxx_mdio_bus *mdio_bus;
-       struct mii_bus *bus;
-
-       list_for_each_entry(mdio_bus, &chip->mdios, list) {
-               bus = mdio_bus->bus;
-
-               mdiobus_unregister(bus);
-       }
-}
-
 static int mv88e6xxx_get_eeprom_len(struct dsa_switch *ds)
 {
        struct mv88e6xxx_chip *chip = ds->priv;