[PATCH 2/2] media: v4l2-async: Make subdev notifier cleanup conditional

[Paul Kocialkowski <paul.kocialkowski@bootlin.com>]

A dedicated subdev notified is registered when using the helper
dedicated to sensors (v4l2_async_register_subdev_sensor_common),
but this is not the case when a driver uses v4l2_async_register_subdev
directly.

As a result, add a conditional check to deal with the dedicated subdev
notifier only when necessary at the async subdev unregister step
(and avoid operating on/freeing an unallocated notifier).

Fixes: aef69d54755d ("media: v4l: fwnode: Add a convenience function for registering sensors")
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index cd9e78c63791..e0f4f7551ff3 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -780,10 +780,12 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
 
 	mutex_lock(&list_lock);
 
-	__v4l2_async_notifier_unregister(sd->subdev_notifier);
-	__v4l2_async_notifier_cleanup(sd->subdev_notifier);
-	kfree(sd->subdev_notifier);
-	sd->subdev_notifier = NULL;
+	if (sd->subdev_notifier) {
+		__v4l2_async_notifier_unregister(sd->subdev_notifier);
+		__v4l2_async_notifier_cleanup(sd->subdev_notifier);
+		kfree(sd->subdev_notifier);
+		sd->subdev_notifier = NULL;
+	}
 
 	if (sd->asd) {
 		struct v4l2_async_notifier *notifier = sd->notifier;
-- 
2.31.1