media: rkisp1: isp: Fix and simplify (un)registration

The rkisp1_isp_register() and rkisp1_isp_unregister() functions don't
destroy the mutex (in the error path for the former). Fix this, simplify
error handling at registration time as media_entity_cleanup() can be
called on an uninitialized entity, and make rkisp1_isp_unregister() and
safe to be called on an unregistered isp subdev to prepare for
simplification of error handling at probe time.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c

@@ -1092,29 +1092,35 @@ int rkisp1_isp_register(struct rkisp1_device *rkisp1)
 	mutex_init(&isp->ops_lock);
 	ret = media_entity_pads_init(&sd->entity, RKISP1_ISP_PAD_MAX, pads);
 	if (ret)
-		return ret;
+		goto error;
 
 	ret = v4l2_device_register_subdev(&rkisp1->v4l2_dev, sd);
 	if (ret) {
 		dev_err(rkisp1->dev, "Failed to register isp subdev\n");
-		goto err_cleanup_media_entity;
+		goto error;
 	}
 
 	rkisp1_isp_init_config(sd, &state);
+
 	return 0;
 
-err_cleanup_media_entity:
+error:
 	media_entity_cleanup(&sd->entity);
-
+	mutex_destroy(&isp->ops_lock);
+	isp->sd.v4l2_dev = NULL;
 	return ret;
 }
 
 void rkisp1_isp_unregister(struct rkisp1_device *rkisp1)
 {
-	struct v4l2_subdev *sd = &rkisp1->isp.sd;
+	struct rkisp1_isp *isp = &rkisp1->isp;
 
-	v4l2_device_unregister_subdev(sd);
-	media_entity_cleanup(&sd->entity);
+	if (!isp->sd.v4l2_dev)
+		return;
+
+	v4l2_device_unregister_subdev(&isp->sd);
+	media_entity_cleanup(&isp->sd.entity);
+	mutex_destroy(&isp->ops_lock);
 }
 
 /* ----------------------------------------------------------------------------