[media] media: Add a function removing all links of a media entity

[firefly-linux-kernel-4.4.55.git] / drivers / media / media-entity.c

diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
index df72f7d99d80f2612ee7c06b4e27a18c909d4a53..cb30ffbd5ba8d534daec5ceab6d709d888844bcf 100644 (file)
--- a/drivers/media/media-entity.c
+++ b/drivers/media/media-entity.c
@@ -429,6 +429,56 @@ media_entity_create_link(struct media_entity *source, u16 source_pad,
 }
 EXPORT_SYMBOL_GPL(media_entity_create_link);
 
+void __media_entity_remove_links(struct media_entity *entity)
+{
+       unsigned int i;
+
+       for (i = 0; i < entity->num_links; i++) {
+               struct media_link *link = &entity->links[i];
+               struct media_entity *remote;
+               unsigned int r = 0;
+
+               if (link->source->entity == entity)
+                       remote = link->sink->entity;
+               else
+                       remote = link->source->entity;
+
+               while (r < remote->num_links) {
+                       struct media_link *rlink = &remote->links[r];
+
+                       if (rlink != link->reverse) {
+                               r++;
+                               continue;
+                       }
+
+                       if (link->source->entity == entity)
+                               remote->num_backlinks--;
+
+                       if (--remote->num_links == 0)
+                               break;
+
+                       /* Insert last entry in place of the dropped link. */
+                       *rlink = remote->links[remote->num_links];
+               }
+       }
+
+       entity->num_links = 0;
+       entity->num_backlinks = 0;
+}
+EXPORT_SYMBOL_GPL(__media_entity_remove_links);
+
+void media_entity_remove_links(struct media_entity *entity)
+{
+       /* Do nothing if the entity is not registered. */
+       if (entity->parent == NULL)
+               return;
+
+       mutex_lock(&entity->parent->graph_mutex);
+       __media_entity_remove_links(entity);
+       mutex_unlock(&entity->parent->graph_mutex);
+}
+EXPORT_SYMBOL_GPL(media_entity_remove_links);
+
 static int __media_entity_setup_link_notify(struct media_link *link, u32 flags)
 {
        int ret;