mux: core: fix double get_device()

class_find_device already does a get_device on the returned device.
So the device returned by of_find_mux_chip_by_node is already referenced
and we should not reference it again (and unref it on error).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mux/core.c b/drivers/mux/core.c
index 2260063b0ea83be7f24e5d780af8bd808c23b427..6e5cf9d9cd9927f4264e3a01394e2b84d80d7d3b 100644 (file)
--- a/drivers/mux/core.c
+++ b/drivers/mux/core.c
@@ -413,6 +413,7 @@ static int of_dev_node_match(struct device *dev, const void *data)
        return dev->of_node == data;
 }
 
+/* Note this function returns a reference to the mux_chip dev. */
 static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np)
 {
        struct device *dev;
@@ -466,6 +467,7 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
            (!args.args_count && (mux_chip->controllers > 1))) {
                dev_err(dev, "%pOF: wrong #mux-control-cells for %pOF\n",
                        np, args.np);
+               put_device(&mux_chip->dev);
                return ERR_PTR(-EINVAL);
        }
 
@@ -476,10 +478,10 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
        if (controller >= mux_chip->controllers) {
                dev_err(dev, "%pOF: bad mux controller %u specified in %pOF\n",
                        np, controller, args.np);
+               put_device(&mux_chip->dev);
                return ERR_PTR(-EINVAL);
        }
 
-       get_device(&mux_chip->dev);
        return &mux_chip->mux[controller];
 }
 EXPORT_SYMBOL_GPL(mux_control_get);