Hi Philipp, On Tuesday 27 August 2013 11:30:51 Philipp Zabel wrote: > 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: Good catch ! I'll fix it in v4, thank you. > 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); -- Regards, Laurent Pinchart _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel