From aa79a84f65b37785ff56b30dc808c88bbc25a91b Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 20 Jul 2016 12:39:02 -0300 Subject: [PATCH] [media] media: entity: Add debug information to graph walk Use dev_dbg() to tell about the progress of the graph traversal algorithm. This is intended to make debugging of the algorithm easier. Signed-off-by: Sakari Ailus Reviewed-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/media-entity.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c index a9998b3..5640ca2 100644 --- a/drivers/media/media-entity.c +++ b/drivers/media/media-entity.c @@ -321,6 +321,8 @@ void media_graph_walk_start(struct media_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_graph_walk_start); @@ -335,6 +337,10 @@ static void media_graph_walk_iter(struct media_graph *graph) /* 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; } @@ -344,16 +350,23 @@ static void media_graph_walk_iter(struct media_graph *graph) /* 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; @@ -365,7 +378,11 @@ struct media_entity *media_graph_walk_next(struct media_graph *graph) while (link_top(graph) != &stack_top(graph)->links) media_graph_walk_iter(graph); - return stack_pop(graph); + entity = stack_pop(graph); + dev_dbg(entity->graph_obj.mdev->dev, + "walk: returning entity '%s'\n", entity->name); + + return entity; } EXPORT_SYMBOL_GPL(media_graph_walk_next); -- 2.7.4