[RFC v4 14/21] media device: Get the media device driver's device

[Sakari Ailus <sakari.ailus@linux.intel.com>]

The struct device of the media device driver (i.e. not that of the media
devnode) is pointed to by the media device. The struct device pointer is
mostly used for debug prints.

Ensure it will stay around as long as the media device does.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/media-device.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index 2e52e44..648c64c 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -724,6 +724,7 @@ static void media_device_release(struct media_devnode *devnode)
 	mdev->entity_internal_idx_max = 0;
 	media_entity_graph_walk_cleanup(&mdev->pm_count_walk);
 	mutex_destroy(&mdev->graph_mutex);
+	put_device(mdev->dev);
 
 	kfree(mdev);
 }
@@ -732,9 +733,15 @@ struct media_device *media_device_alloc(struct device *dev)
 {
 	struct media_device *mdev;
 
+	dev = get_device(dev);
+	if (!dev)
+		return NULL;
+
 	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
-	if (!mdev)
+	if (!mdev) {
+		put_device(dev);
 		return NULL;
+	}
 
 	mdev->dev = dev;
 	media_device_init(mdev);
-- 
2.1.4