Hi Laurent, I have another small issue with the graph helpers below: Am Samstag, den 10.08.2013, 01:03 +0200 schrieb Laurent Pinchart: [...] > +/* ----------------------------------------------------------------------------- > * Graph Helpers > */ > > @@ -420,6 +599,161 @@ int display_entity_link_graph(struct device *dev, struct list_head *entities) > } > EXPORT_SYMBOL_GPL(display_entity_link_graph); > > +#ifdef CONFIG_OF > + > +static int display_of_entity_link_entity(struct device *dev, > + struct display_entity *entity, > + struct list_head *entities, > + struct display_entity *root) > +{ > + u32 link_flags = MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED; > + const struct device_node *node = entity->dev->of_node; > + struct media_entity *local = &entity->entity; > + struct device_node *ep = NULL; > + int ret = 0; > + > + dev_dbg(dev, "creating links for entity %s\n", local->name); > + > + while (1) { > + struct media_entity *remote = NULL; > + struct media_pad *remote_pad; > + struct media_pad *local_pad; > + struct display_of_link link; > + struct display_entity *ent; > + struct device_node *next; > + > + /* Get the next endpoint and parse its link. */ > + next = display_of_get_next_endpoint(node, ep); > + if (next == NULL) > + break; > + > + of_node_put(ep); > + ep = next; > + > + dev_dbg(dev, "processing endpoint %s\n", ep->full_name); > + > + ret = display_of_parse_link(ep, &link); > + if (ret < 0) { > + dev_err(dev, "failed to parse link for %s\n", > + ep->full_name); > + continue; > + } > + > + /* Skip source pads, they will be processed from the other end of > + * the link. > + */ > + if (link.local_port >= local->num_pads) { > + dev_err(dev, "invalid port number %u on %s\n", > + link.local_port, link.local_node->full_name); > + display_of_put_link(&link); > + ret = -EINVAL; > + break; > + } > + > + local_pad = &local->pads[link.local_port]; > + > + if (local_pad->flags & MEDIA_PAD_FL_SOURCE) { > + dev_dbg(dev, "skipping source port %s:%u\n", > + link.local_node->full_name, link.local_port); > + display_of_put_link(&link); > + continue; > + } > + > + /* Find the remote entity. If not found, just skip the link as > + * it goes out of scope of the entities handled by the notifier. > + */ > + list_for_each_entry(ent, entities, list) { > + if (ent->dev->of_node == link.remote_node) { > + remote = &ent->entity; > + break; > + } > + } > + > + if (root->dev->of_node == link.remote_node) > + remote = &root->entity; > + > + if (remote == NULL) { > + dev_dbg(dev, "no entity found for %s\n", > + link.remote_node->full_name); > + display_of_put_link(&link); > + continue; > + } > + > + if (link.remote_port >= remote->num_pads) { > + dev_err(dev, "invalid port number %u on %s\n", > + link.remote_port, link.remote_node->full_name); > + display_of_put_link(&link); > + ret = -EINVAL; > + break; > + } > + > + remote_pad = &remote->pads[link.remote_port]; > + > + display_of_put_link(&link); > + > + /* Create the media link. */ > + dev_dbg(dev, "creating %s:%u -> %s:%u link\n", > + remote->name, remote_pad->index, > + local->name, local_pad->index); > + > + ret = media_entity_create_link(remote, remote_pad->index, > + local, local_pad->index, > + link_flags); > + if (ret < 0) { > + dev_err(dev, > + "failed to create %s:%u -> %s:%u link\n", > + remote->name, remote_pad->index, > + local->name, local_pad->index); > + break; > + } > + } > + > + of_node_put(ep); > + return ret; > +} > + > +/** > + * display_of_entity_link_graph - Link all entities in a graph > + * @dev: device used to print debugging and error messages > + * @root: optional root display entity > + * @entities: list of display entities in the graph > + * > + * This function creates media controller links for all entities in a graph > + * based on the device tree graph representation. It relies on all entities > + * having been instantiated from the device tree. > + * > + * The list of entities is typically taken directly from a display notifier > + * done list. It will thus not include any display entity not handled by the > + * notifier, such as entities directly accessible by the caller without going > + * through the notification process. The optional root entity parameter can be > + * used to pass such a display entity and include it in the graph. For all > + * practical purpose the root entity is handled is if it was part of the > + * entities list. > + * > + * Return 0 on success or a negative error code otherwise. > + */ > +int display_of_entity_link_graph(struct device *dev, struct list_head *entities, > + struct display_entity *root) > +{ > + struct display_entity *entity; > + int ret; > + > + list_for_each_entry(entity, entities, list) { > + if (WARN_ON(entity->match->type != DISPLAY_ENTITY_BUS_DT)) > + return -EINVAL; > + > + ret = display_of_entity_link_entity(dev, entity, entities, > + root); > + if (ret < 0) > + return ret; > + } > + > + return display_of_entity_link_entity(dev, root, entities, root); > +} > +EXPORT_SYMBOL_GPL(display_of_entity_link_graph); The root display entity given to display_of_entity_link_graph is documented to be optional. Therefore, do not try to dereference root if it is NULL: diff --git a/drivers/video/display/display-core.c b/drivers/video/display/display-core.c index 328ead7..6c8094f 100644 --- a/drivers/video/display/display-core.c +++ b/drivers/video/display/display-core.c @@ -669,7 +669,7 @@ static int display_of_entity_link_entity(struct device *dev, } } - if (root->dev->of_node == link.remote_node) + if (root && root->dev->of_node == link.remote_node) remote = &root->entity; if (remote == NULL) { @@ -748,6 +748,9 @@ int display_of_entity_link_graph(struct device *dev, struct list_head *entities, return ret; } + if (!root) + return 0; + return display_of_entity_link_entity(dev, root, entities, root); } EXPORT_SYMBOL_GPL(display_of_entity_link_graph); -- 1.8.4.rc3 regards Philipp _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel