phylib: fix premature freeing of struct mii_bus

Commit 46abc02175b3c246dd5141d878f565a8725060c9 ("phylib: give mdio
buses a device tree presence") added a call to device_unregister() in
a situation where the caller did not intend for the device to be
freed yet, but apart from just unregistering the device from the
system, device_unregister() does an additional put_device() that is
intended to free it.

The right function to use in this situation is device_del(), which
unregisters the device from the system like device_unregister() does,
but without dropping the reference count an additional time.

Bug report from Bryan Wu <cooloney@kernel.org>.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Tested-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index d0ed1ef284a80404510e8f169537f40e4cb678a3..536bda1f428b6c09360be41448f7b0b7d4c16679 100644 (file)
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -136,7 +136,7 @@ void mdiobus_unregister(struct mii_bus *bus)
        BUG_ON(bus->state != MDIOBUS_REGISTERED);
        bus->state = MDIOBUS_UNREGISTERED;
 
-       device_unregister(&bus->dev);
+       device_del(&bus->dev);
        for (i = 0; i < PHY_MAX_ADDR; i++) {
                if (bus->phy_map[i])
                        device_unregister(&bus->phy_map[i]->dev);