[PATCH v3 04/31] v4l: mc: Start walk from a specific pad in use count calculation

[Jacopo Mondi]

From: Sakari Ailus <sakari.ai...@linux.intel.com>

With the addition of the recent has_route() media entity op, the pads of a
media entity are no longer all interconnected. This has to be taken into
account in power management.

Prepare for the addition of a helper function supporting S_ROUTING.

Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+rene...@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+rene...@jmondi.org>
---
 drivers/media/v4l2-core/v4l2-mc.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-mc.c 
b/drivers/media/v4l2-core/v4l2-mc.c
index 98edd47b2f0a..558dec225838 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -332,17 +332,16 @@ EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
 
 /*
  * pipeline_pm_use_count - Count the number of users of a pipeline
- * @entity: The entity
+ * @pad: Any pad along the pipeline
  *
  * Return the total number of users of all video device nodes in the pipeline.
  */
-static int pipeline_pm_use_count(struct media_entity *entity,
-       struct media_graph *graph)
+static int pipeline_pm_use_count(struct media_pad *pad,
+                                struct media_graph *graph)
 {
-       struct media_pad *pad;
        int use = 0;
 
-       media_graph_walk_start(graph, entity->pads);
+       media_graph_walk_start(graph, pad);
 
        while ((pad = media_graph_walk_next(graph))) {
                if (is_media_entity_v4l2_video_device(pad->entity))
@@ -388,7 +387,7 @@ static int pipeline_pm_power_one(struct media_entity 
*entity, int change)
 
 /*
  * pipeline_pm_power - Apply power change to all entities in a pipeline
- * @entity: The entity
+ * @pad: Any pad along the pipeline
  * @change: Use count change
  *
  * Walk the pipeline to update the use count and the power state of all 
non-node
@@ -396,16 +395,16 @@ static int pipeline_pm_power_one(struct media_entity 
*entity, int change)
  *
  * Return 0 on success or a negative error code on failure.
  */
-static int pipeline_pm_power(struct media_entity *entity, int change,
+static int pipeline_pm_power(struct media_pad *pad, int change,
        struct media_graph *graph)
 {
-       struct media_pad *tmp_pad, *pad;
+       struct media_pad *tmp_pad, *first = pad;
        int ret = 0;
 
        if (!change)
                return 0;
 
-       media_graph_walk_start(graph, entity->pads);
+       media_graph_walk_start(graph, pad);
 
        while (!ret && (pad = media_graph_walk_next(graph)))
                if (is_media_entity_v4l2_subdev(pad->entity))
@@ -414,7 +413,7 @@ static int pipeline_pm_power(struct media_entity *entity, 
int change,
        if (!ret)
                return ret;
 
-       media_graph_walk_start(graph, entity->pads);
+       media_graph_walk_start(graph, first);
 
        while ((tmp_pad = media_graph_walk_next(graph))
               && tmp_pad != pad)
@@ -437,7 +436,7 @@ int v4l2_pipeline_pm_use(struct media_entity *entity, int 
use)
        WARN_ON(entity->use_count < 0);
 
        /* Apply power change to connected non-nodes. */
-       ret = pipeline_pm_power(entity, change, &mdev->pm_count_walk);
+       ret = pipeline_pm_power(entity->pads, change, &mdev->pm_count_walk);
        if (ret < 0)
                entity->use_count -= change;
 
@@ -451,8 +450,8 @@ int v4l2_pipeline_link_notify(struct media_link *link, u32 
flags,
                              unsigned int notification)
 {
        struct media_graph *graph = &link->graph_obj.mdev->pm_count_walk;
-       struct media_entity *source = link->source->entity;
-       struct media_entity *sink = link->sink->entity;
+       struct media_pad *source = link->source;
+       struct media_pad *sink = link->sink;
        int source_use;
        int sink_use;
        int ret = 0;
-- 
2.20.1