V4L/DVB (11044): v4l2-device: add v4l2_device_disconnect

Call v4l2_device_disconnect when the parent of a hotpluggable device
disconnects. This ensures that you do not have a pointer to a device that
is no longer present.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c
index b3dcb8454379..94aa485ade52 100644
--- a/drivers/media/video/v4l2-device.c
+++ b/drivers/media/video/v4l2-device.c
@@ -49,19 +49,26 @@ int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
 }
 EXPORT_SYMBOL_GPL(v4l2_device_register);
 
+void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
+{
+        if (v4l2_dev->dev) {
+                dev_set_drvdata(v4l2_dev->dev, NULL);
+                v4l2_dev->dev = NULL;
+        }
+}
+EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
+
 void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
 {
         struct v4l2_subdev *sd, *next;
 
         if (v4l2_dev == NULL)
                 return;
-        if (v4l2_dev->dev)
-                dev_set_drvdata(v4l2_dev->dev, NULL);
+        v4l2_device_disconnect(v4l2_dev);
+
         /* Unregister subdevs */
         list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list)
                 v4l2_device_unregister_subdev(sd);
-
-        v4l2_dev->dev = NULL;
 }
 EXPORT_SYMBOL_GPL(v4l2_device_unregister);