[PATCH 16/26] media-device: Postpone graph object removal until free

From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: linux-media@vger.kernel.org
Cc: laurent.pinchart@ideasonboard.com, hverkuil@xs4all.nl
Subject: [PATCH 16/26] media-device: Postpone graph object removal until free
Date: Wed,  1 Feb 2023 23:45:25 +0200	[thread overview]
Message-ID: <20230201214535.347075-17-sakari.ailus@linux.intel.com> (raw)
In-Reply-To: <20230201214535.347075-1-sakari.ailus@linux.intel.com>

The media device itself will be unregistered based on it being unbound and
driver's remove callback being called. The graph objects themselves may
still be in use; rely on the media device release callback to release
them.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/mc/mc-device.c | 53 +++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 28 deletions(-)

diff --git a/drivers/media/mc/mc-device.c b/drivers/media/mc/mc-device.c
index c13cbdfdbaab..00c44752b4a1 100644
--- a/drivers/media/mc/mc-device.c
+++ b/drivers/media/mc/mc-device.c
@@ -707,8 +707,33 @@ EXPORT_SYMBOL_GPL(media_device_unregister_entity_notify);
 
 static void __media_device_release(struct media_device *mdev)
 {
+	struct media_entity *entity;
+	struct media_entity *next;
+	struct media_interface *intf, *tmp_intf;
+	struct media_entity_notify *notify, *nextp;
+
 	dev_dbg(mdev->dev, "Media device released\n");
 
+	/* Remove all entities from the media device */
+	list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
+		__media_device_unregister_entity(entity);
+
+	/* Remove all entity_notify callbacks from the media device */
+	list_for_each_entry_safe(notify, nextp, &mdev->entity_notify, list)
+		__media_device_unregister_entity_notify(mdev, notify);
+
+	/* Remove all interfaces from the media device */
+	list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
+				 graph_obj.list) {
+		/*
+		 * Unlink the interface, but don't free it here; the
+		 * module which created it is responsible for freeing
+		 * it
+		 */
+		__media_remove_intf_links(intf);
+		media_gobj_destroy(&intf->graph_obj);
+	}
+
 	ida_destroy(&mdev->entity_internal_idx);
 	mdev->entity_internal_idx_max = 0;
 	media_graph_walk_cleanup(&mdev->pm_count_walk);
@@ -799,42 +824,14 @@ EXPORT_SYMBOL_GPL(__media_device_register);
 
 void media_device_unregister(struct media_device *mdev)
 {
-	struct media_entity *entity;
-	struct media_entity *next;
-	struct media_interface *intf, *tmp_intf;
-	struct media_entity_notify *notify, *nextp;
-
 	if (mdev == NULL)
 		return;
 
 	mutex_lock(&mdev->graph_mutex);
-
-	/* Check if mdev was ever registered at all */
 	if (!media_devnode_is_registered(&mdev->devnode)) {
 		mutex_unlock(&mdev->graph_mutex);
 		return;
 	}
-
-	/* Remove all entities from the media device */
-	list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
-		__media_device_unregister_entity(entity);
-
-	/* Remove all entity_notify callbacks from the media device */
-	list_for_each_entry_safe(notify, nextp, &mdev->entity_notify, list)
-		__media_device_unregister_entity_notify(mdev, notify);
-
-	/* Remove all interfaces from the media device */
-	list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
-				 graph_obj.list) {
-		/*
-		 * Unlink the interface, but don't free it here; the
-		 * module which created it is responsible for freeing
-		 * it
-		 */
-		__media_remove_intf_links(intf);
-		media_gobj_destroy(&intf->graph_obj);
-	}
-
 	mutex_unlock(&mdev->graph_mutex);
 
 	device_remove_file(&mdev->devnode.dev, &dev_attr_model);
-- 
2.30.2

