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net: mdio-mux: fix unbalanced put_device

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commit 60f786525032432af1b7d9b8935cb12936244ccd upstream.

mdio_mux_uninit() call put_device (unconditionally) because of
of_mdio_find_bus() in mdio_mux_init.
But of_mdio_find_bus is only called if mux_bus is empty.
If mux_bus is set, mdio_mux_uninit will print a "refcount_t: underflow"
trace.

This patch add a get_device in the other branch of "if (mux_bus)".

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Corentin Labbe 2017-09-01 13:56:04 +02:00 committed by Greg Kroah-Hartman
parent 2a75be3891
commit 5ae4974c95
1 changed files with 2 additions and 4 deletions
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6
drivers/net/phy/mdio-mux.c
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@ -117,6 +117,7 @@ int mdio_mux_init(struct device *dev,
} else {
parent_bus_node = NULL;
parent_bus = mux_bus;
get_device(&parent_bus->dev);
}
pb = devm_kzalloc(dev, sizeof(*pb), GFP_KERNEL);
@ -182,9 +183,7 @@ int mdio_mux_init(struct device *dev,
devm_kfree(dev, pb);
err_pb_kz:
/* balance the reference of_mdio_find_bus() took */
if (!mux_bus)
put_device(&parent_bus->dev);
put_device(&parent_bus->dev);
err_parent_bus:
of_node_put(parent_bus_node);
return ret_val;
@ -202,7 +201,6 @@ void mdio_mux_uninit(void *mux_handle)
cb = cb->next;
}
/* balance the reference of_mdio_find_bus() in mdio_mux_init() took */
put_device(&pb->mii_bus->dev);
}
EXPORT_SYMBOL_GPL(mdio_mux_uninit);