1 files changed, 91 insertions, 75 deletions

diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
index f9f723f5e4f0..5640ca29da8c 100644
--- a/drivers/media/media-entity.c
+++ b/drivers/media/media-entity.c
@@ -14,10 +14,6 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include <linux/bitmap.h>
@@ -258,7 +254,7 @@ media_entity_other(struct media_entity *entity, struct media_link *link)
 }
 
 /* push an entity to traversal stack */
-static void stack_push(struct media_entity_graph *graph,
+static void stack_push(struct media_graph *graph,
 		       struct media_entity *entity)
 {
 	if (graph->top == MEDIA_ENTITY_ENUM_MAX_DEPTH - 1) {
@@ -270,7 +266,7 @@ static void stack_push(struct media_entity_graph *graph,
 	graph->stack[graph->top].entity = entity;
 }
 
-static struct media_entity *stack_pop(struct media_entity_graph *graph)
+static struct media_entity *stack_pop(struct media_graph *graph)
 {
 	struct media_entity *entity;
 
@@ -289,35 +285,35 @@ static struct media_entity *stack_pop(struct media_entity_graph *graph)
 #define MEDIA_ENTITY_MAX_PADS		512
 
 /**
- * media_entity_graph_walk_init - Allocate resources for graph walk
+ * media_graph_walk_init - Allocate resources for graph walk
  * @graph: Media graph structure that will be used to walk the graph
  * @mdev: Media device
  *
  * Reserve resources for graph walk in media device's current
  * state. The memory must be released using
- * media_entity_graph_walk_free().
+ * media_graph_walk_free().
  *
  * Returns error on failure, zero on success.
  */
-__must_check int media_entity_graph_walk_init(
-	struct media_entity_graph *graph, struct media_device *mdev)
+__must_check int media_graph_walk_init(
+	struct media_graph *graph, struct media_device *mdev)
 {
 	return media_entity_enum_init(&graph->ent_enum, mdev);
 }
-EXPORT_SYMBOL_GPL(media_entity_graph_walk_init);
+EXPORT_SYMBOL_GPL(media_graph_walk_init);
 
 /**
- * media_entity_graph_walk_cleanup - Release resources related to graph walking
+ * media_graph_walk_cleanup - Release resources related to graph walking
  * @graph: Media graph structure that was used to walk the graph
  */
-void media_entity_graph_walk_cleanup(struct media_entity_graph *graph)
+void media_graph_walk_cleanup(struct media_graph *graph)
 {
 	media_entity_enum_cleanup(&graph->ent_enum);
 }
-EXPORT_SYMBOL_GPL(media_entity_graph_walk_cleanup);
+EXPORT_SYMBOL_GPL(media_graph_walk_cleanup);
 
-void media_entity_graph_walk_start(struct media_entity_graph *graph,
-				   struct media_entity *entity)
+void media_graph_walk_start(struct media_graph *graph,
+			    struct media_entity *entity)
 {
 	media_entity_enum_zero(&graph->ent_enum);
 	media_entity_enum_set(&graph->ent_enum, entity);
@@ -325,12 +321,52 @@ void media_entity_graph_walk_start(struct media_entity_graph *graph,
 	graph->top = 0;
 	graph->stack[graph->top].entity = NULL;
 	stack_push(graph, entity);
+	dev_dbg(entity->graph_obj.mdev->dev,
+		"begin graph walk at '%s'\n", entity->name);
 }
-EXPORT_SYMBOL_GPL(media_entity_graph_walk_start);
+EXPORT_SYMBOL_GPL(media_graph_walk_start);
 
-struct media_entity *
-media_entity_graph_walk_next(struct media_entity_graph *graph)
+static void media_graph_walk_iter(struct media_graph *graph)
 {
+	struct media_entity *entity = stack_top(graph);
+	struct media_link *link;
+	struct media_entity *next;
+
+	link = list_entry(link_top(graph), typeof(*link), list);
+
+	/* The link is not enabled so we do not follow. */
+	if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
+		link_top(graph) = link_top(graph)->next;
+		dev_dbg(entity->graph_obj.mdev->dev,
+			"walk: skipping disabled link '%s':%u -> '%s':%u\n",
+			link->source->entity->name, link->source->index,
+			link->sink->entity->name, link->sink->index);
+		return;
+	}
+
+	/* Get the entity in the other end of the link . */
+	next = media_entity_other(entity, link);
+
+	/* Has the entity already been visited? */
+	if (media_entity_enum_test_and_set(&graph->ent_enum, next)) {
+		link_top(graph) = link_top(graph)->next;
+		dev_dbg(entity->graph_obj.mdev->dev,
+			"walk: skipping entity '%s' (already seen)\n",
+			next->name);
+		return;
+	}
+
+	/* Push the new entity to stack and start over. */
+	link_top(graph) = link_top(graph)->next;
+	stack_push(graph, next);
+	dev_dbg(entity->graph_obj.mdev->dev, "walk: pushing '%s' on stack\n",
+		next->name);
+}
+
+struct media_entity *media_graph_walk_next(struct media_graph *graph)
+{
+	struct media_entity *entity;
+
 	if (stack_top(graph) == NULL)
 		return NULL;
 
@@ -339,59 +375,39 @@ media_entity_graph_walk_next(struct media_entity_graph *graph)
 	 * top of the stack until no more entities on the level can be
 	 * found.
 	 */
-	while (link_top(graph) != &stack_top(graph)->links) {
-		struct media_entity *entity = stack_top(graph);
-		struct media_link *link;
-		struct media_entity *next;
-
-		link = list_entry(link_top(graph), typeof(*link), list);
-
-		/* The link is not enabled so we do not follow. */
-		if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
-			link_top(graph) = link_top(graph)->next;
-			continue;
-		}
+	while (link_top(graph) != &stack_top(graph)->links)
+		media_graph_walk_iter(graph);
 
-		/* Get the entity in the other end of the link . */
-		next = media_entity_other(entity, link);
+	entity = stack_pop(graph);
+	dev_dbg(entity->graph_obj.mdev->dev,
+		"walk: returning entity '%s'\n", entity->name);
 
-		/* Has the entity already been visited? */
-		if (media_entity_enum_test_and_set(&graph->ent_enum, next)) {
-			link_top(graph) = link_top(graph)->next;
-			continue;
-		}
-
-		/* Push the new entity to stack and start over. */
-		link_top(graph) = link_top(graph)->next;
-		stack_push(graph, next);
-	}
-
-	return stack_pop(graph);
+	return entity;
 }
-EXPORT_SYMBOL_GPL(media_entity_graph_walk_next);
+EXPORT_SYMBOL_GPL(media_graph_walk_next);
 
 /* -----------------------------------------------------------------------------
  * Pipeline management
  */
 
-__must_check int __media_entity_pipeline_start(struct media_entity *entity,
-					       struct media_pipeline *pipe)
+__must_check int __media_pipeline_start(struct media_entity *entity,
+					struct media_pipeline *pipe)
 {
 	struct media_device *mdev = entity->graph_obj.mdev;
-	struct media_entity_graph *graph = &pipe->graph;
+	struct media_graph *graph = &pipe->graph;
 	struct media_entity *entity_err = entity;
 	struct media_link *link;
 	int ret;
 
 	if (!pipe->streaming_count++) {
-		ret = media_entity_graph_walk_init(&pipe->graph, mdev);
+		ret = media_graph_walk_init(&pipe->graph, mdev);
 		if (ret)
 			goto error_graph_walk_start;
 	}
 
-	media_entity_graph_walk_start(&pipe->graph, entity);
+	media_graph_walk_start(&pipe->graph, entity);
 
-	while ((entity = media_entity_graph_walk_next(graph))) {
+	while ((entity = media_graph_walk_next(graph))) {
 		DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS);
 		DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS);
 
@@ -441,7 +457,7 @@ __must_check int __media_entity_pipeline_start(struct media_entity *entity,
 			ret = entity->ops->link_validate(link);
 			if (ret < 0 && ret != -ENOIOCTLCMD) {
 				dev_dbg(entity->graph_obj.mdev->dev,
-					"link validation failed for \"%s\":%u -> \"%s\":%u, error %d\n",
+					"link validation failed for '%s':%u -> '%s':%u, error %d\n",
 					link->source->entity->name,
 					link->source->index,
 					entity->name, link->sink->index, ret);
@@ -455,7 +471,7 @@ __must_check int __media_entity_pipeline_start(struct media_entity *entity,
 		if (!bitmap_full(active, entity->num_pads)) {
 			ret = -ENOLINK;
 			dev_dbg(entity->graph_obj.mdev->dev,
-				"\"%s\":%u must be connected by an enabled link\n",
+				"'%s':%u must be connected by an enabled link\n",
 				entity->name,
 				(unsigned)find_first_zero_bit(
 					active, entity->num_pads));
@@ -470,11 +486,11 @@ error:
 	 * Link validation on graph failed. We revert what we did and
 	 * return the error.
 	 */
-	media_entity_graph_walk_start(graph, entity_err);
+	media_graph_walk_start(graph, entity_err);
 
-	while ((entity_err = media_entity_graph_walk_next(graph))) {
-		/* don't let the stream_count go negative */
-		if (entity->stream_count > 0) {
+	while ((entity_err = media_graph_walk_next(graph))) {
+		/* Sanity check for negative stream_count */
+		if (!WARN_ON_ONCE(entity_err->stream_count <= 0)) {
 			entity_err->stream_count--;
 			if (entity_err->stream_count == 0)
 				entity_err->pipe = NULL;
@@ -490,37 +506,37 @@ error:
 
 error_graph_walk_start:
 	if (!--pipe->streaming_count)
-		media_entity_graph_walk_cleanup(graph);
+		media_graph_walk_cleanup(graph);
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(__media_entity_pipeline_start);
+EXPORT_SYMBOL_GPL(__media_pipeline_start);
 
-__must_check int media_entity_pipeline_start(struct media_entity *entity,
-					     struct media_pipeline *pipe)
+__must_check int media_pipeline_start(struct media_entity *entity,
+				      struct media_pipeline *pipe)
 {
 	struct media_device *mdev = entity->graph_obj.mdev;
 	int ret;
 
 	mutex_lock(&mdev->graph_mutex);
-	ret = __media_entity_pipeline_start(entity, pipe);
+	ret = __media_pipeline_start(entity, pipe);
 	mutex_unlock(&mdev->graph_mutex);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(media_entity_pipeline_start);
+EXPORT_SYMBOL_GPL(media_pipeline_start);
 
-void __media_entity_pipeline_stop(struct media_entity *entity)
+void __media_pipeline_stop(struct media_entity *entity)
 {
-	struct media_entity_graph *graph = &entity->pipe->graph;
+	struct media_graph *graph = &entity->pipe->graph;
 	struct media_pipeline *pipe = entity->pipe;
 
 
 	WARN_ON(!pipe->streaming_count);
-	media_entity_graph_walk_start(graph, entity);
+	media_graph_walk_start(graph, entity);
 
-	while ((entity = media_entity_graph_walk_next(graph))) {
-		/* don't let the stream_count go negative */
-		if (entity->stream_count > 0) {
+	while ((entity = media_graph_walk_next(graph))) {
+		/* Sanity check for negative stream_count */
+		if (!WARN_ON_ONCE(entity->stream_count <= 0)) {
 			entity->stream_count--;
 			if (entity->stream_count == 0)
 				entity->pipe = NULL;
@@ -528,20 +544,20 @@ void __media_entity_pipeline_stop(struct media_entity *entity)
 	}
 
 	if (!--pipe->streaming_count)
-		media_entity_graph_walk_cleanup(graph);
+		media_graph_walk_cleanup(graph);
 
 }
-EXPORT_SYMBOL_GPL(__media_entity_pipeline_stop);
+EXPORT_SYMBOL_GPL(__media_pipeline_stop);
 
-void media_entity_pipeline_stop(struct media_entity *entity)
+void media_pipeline_stop(struct media_entity *entity)
 {
 	struct media_device *mdev = entity->graph_obj.mdev;
 
 	mutex_lock(&mdev->graph_mutex);
-	__media_entity_pipeline_stop(entity);
+	__media_pipeline_stop(entity);
 	mutex_unlock(&mdev->graph_mutex);
 }
-EXPORT_SYMBOL_GPL(media_entity_pipeline_stop);
+EXPORT_SYMBOL_GPL(media_pipeline_stop);
 
 /* -----------------------------------------------------------------------------
  * Module use count