0051-media-entity-graph-walk-starting-from-pad.patch

From 2c326609428d70a5e31c6f5d52cff237ebfcbf6b Mon Sep 17 00:00:00 2001
From: Meng Wei <wei.meng@intel.com>
Date: Fri, 26 Oct 2018 09:52:28 +0800
Subject: [PATCH 08/25] media:entity: graph walk starting from pad

This function initializes the graph traversal structure to walk
the entities graph starting at the given entity and pad.
As some entity may be on the cross node on pipeline, so add one
parameter to start the graph traverse.

Signed-off-by: Chang Ying <ying.chang@intel.com>
Signed-off-by: Meng Wei <wei.meng@intel.com>
---
 drivers/media/media-entity.c      | 4 +++-
 drivers/media/v4l2-core/v4l2-mc.c | 4 ++++
 include/media/media-entity.h      | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
index 0ad584518db7..a0aeee60cb5d 100644
--- a/drivers/media/media-entity.c
+++ b/drivers/media/media-entity.c
@@ -332,7 +332,9 @@ void media_graph_walk_start(struct media_graph *graph,
 
 	graph->top = 0;
 	graph->stack[graph->top].entity = NULL;
-	stack_push(graph, entity, 0, -1);
+	stack_push(graph, entity,
+			entity->start ? entity->start->index : 0, -1);
+	entity->start = NULL;
 	dev_dbg(entity->graph_obj.mdev->dev,
 		"begin graph walk at '%s'\n", entity->name);
 }
diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index 0fc185a2ce90..031418bb0edf 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -375,6 +375,8 @@ int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
 	int sink_use;
 	int ret = 0;
 
+	source->start = link->source;
+	sink->start = link->sink;
 	source_use = pipeline_pm_use_count(source, graph);
 	sink_use = pipeline_pm_use_count(sink, graph);
 
@@ -383,6 +385,8 @@ int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
 		/* Powering off entities is assumed to never fail. */
 		pipeline_pm_power(source, -sink_use, graph);
 		pipeline_pm_power(sink, -source_use, graph);
+		source->use_count = 0;
+		sink->use_count = 0;
 		return 0;
 	}
 
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index 0faaf936302b..95c27c39e42f 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -284,6 +284,7 @@ struct media_entity {
 	int internal_idx;
 
 	struct media_pad *pads;
+	struct media_pad *start;
 	struct list_head links;
 
 	const struct media_entity_operations *ops;
-- 
2.19.1