media: vimc: free vimc_cap_device when the last user disappears

Don't free vimc_cap_device immediately, instead do this
in the video_device release function which is called when the
last user closes the video device. Only then is it safe to
free the memory.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/vimc/vimc-capture.c

@@ -338,6 +338,15 @@ static const struct media_entity_operations vimc_cap_mops = {
 	.link_validate		= vimc_link_validate,
 };
 
+static void vimc_cap_release(struct video_device *vdev)
+{
+	struct vimc_cap_device *vcap =
+		container_of(vdev, struct vimc_cap_device, vdev);
+
+	vimc_pads_cleanup(vcap->ved.pads);
+	kfree(vcap);
+}
+
 static void vimc_cap_comp_unbind(struct device *comp, struct device *master,
 				 void *master_data)
 {
@@ -348,8 +357,6 @@ static void vimc_cap_comp_unbind(struct device *comp, struct device *master,
 	vb2_queue_release(&vcap->queue);
 	media_entity_cleanup(ved->ent);
 	video_unregister_device(&vcap->vdev);
-	vimc_pads_cleanup(vcap->ved.pads);
-	kfree(vcap);
 }
 
 static void *vimc_cap_process_frame(struct vimc_ent_device *ved,
@@ -467,7 +474,7 @@ static int vimc_cap_comp_bind(struct device *comp, struct device *master,
 	vdev = &vcap->vdev;
 	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
 	vdev->entity.ops = &vimc_cap_mops;
-	vdev->release = video_device_release_empty;
+	vdev->release = vimc_cap_release;
 	vdev->fops = &vimc_cap_fops;
 	vdev->ioctl_ops = &vimc_cap_ioctl_ops;
 	vdev->lock = &vcap->lock;