struct media_entity *
media_entity_graph_walk_next(struct media_entity_graph *graph)
{
if (stack_top(graph) == NULL)
return NULL;
while (link_top(graph) < stack_top(graph)->num_links) {
struct media_entity *entity = stack_top(graph);
struct media_link *link = &entity->links[link_top(graph)];
struct media_entity *next;
if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
link_top(graph)++;
continue;
}
next = media_entity_other(entity, link);
if (next == stack_peek(graph)) {
link_top(graph)++;
continue;
}
link_top(graph)++;
stack_push(graph, next);
}
return stack_pop(graph);
}
/**
* media_entity_graph_walk_next - Get the next entity in the graph
* @graph: Media graph structure
*
* Perform a depth-first traversal of the given media entities graph.
*
* The graph structure must have been previously initialized with a call to
* media_entity_graph_walk_start().
*
* Return the next entity in the graph or NULL if the whole graph have been
* traversed.
*/
struct media_entity *
media_entity_graph_walk_next(struct media_entity_graph *graph)
{
if (stack_top(graph) == NULL)
return NULL;
/*
* Depth first search. Push entity to stack and continue from
* top of the stack until no more entities on the level can be
* found.
*/
while (link_top(graph) < stack_top(graph)->num_links) {
struct media_entity *entity = stack_top(graph);
struct media_link *link = &entity->links[link_top(graph)];
struct media_entity *next;
/* The link is not enabled so we do not follow. */
if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
link_top(graph)++;
continue;
}
/* Get the entity in the other end of the link . */
next = media_entity_other(entity, link);
if (WARN_ON(next->id >= MEDIA_ENTITY_ENUM_MAX_ID))
return NULL;
/* Has the entity already been visited? */
if (__test_and_set_bit(next->id, graph->entities)) {
link_top(graph)++;
continue;
}
/* Push the new entity to stack and start over. */
link_top(graph)++;
stack_push(graph, next);
}
return stack_pop(graph);
}
/**
* media_entity_graph_walk_next - Get the next entity in the graph
* @graph: Media graph structure
*
* Perform a depth-first traversal of the given media entities graph.
*
* The graph structure must have been previously initialized with a call to
* media_entity_graph_walk_start().
*
* Return the next entity in the graph or NULL if the whole graph have been
* traversed.
*/
struct media_entity *
media_entity_graph_walk_next(struct media_entity_graph *graph)
{
if (stack_top(graph) == NULL)
return NULL;
/*
* Depth first search. Push entity to stack and continue from
* top of the stack until no more entities on the level can be
* found.
*/
while (link_top(graph) < stack_top(graph)->num_links) {
struct media_entity *entity = stack_top(graph);
struct media_link *link = &entity->links[link_top(graph)];
struct media_entity *next;
/* The link is not enabled so we do not follow. */
if (!(link->flags & MEDIA_LNK_FL_ENABLED)) {
link_top(graph)++;
continue;
}
/* Get the entity in the other end of the link . */
next = media_entity_other(entity, link);
/* Was it the entity we came here from? */
if (next == stack_peek(graph)) {
link_top(graph)++;
continue;
}
/* Push the new entity to stack and start over. */
link_top(graph)++;
stack_push(graph, next);
}
return stack_pop(graph);
}
