Merge tag 'drm-misc-next-fixes-2022-04-07' of git://anongit.freedesktop.org/drm/drm...

[linux-2.6-microblaze.git] / drivers / gpu / drm / drm_of.c

diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
index 026e4e2..f4df344 100644 (file)
--- a/drivers/gpu/drm/drm_of.c
+++ b/drivers/gpu/drm/drm_of.c
@@ -214,6 +214,29 @@ int drm_of_encoder_active_endpoint(struct device_node *node,
 }
 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
 
+static int find_panel_or_bridge(struct device_node *node,
+                               struct drm_panel **panel,
+                               struct drm_bridge **bridge)
+{
+       if (panel) {
+               *panel = of_drm_find_panel(node);
+               if (!IS_ERR(*panel))
+                       return 0;
+
+               /* Clear the panel pointer in case of error. */
+               *panel = NULL;
+       }
+
+       /* No panel found yet, check for a bridge next. */
+       if (bridge) {
+               *bridge = of_drm_find_bridge(node);
+               if (*bridge)
+                       return 0;
+       }
+
+       return -EPROBE_DEFER;
+}
+
 /**
  * drm_of_find_panel_or_bridge - return connected panel or bridge device
  * @np: device tree node containing encoder output ports
@@ -236,66 +259,44 @@ int drm_of_find_panel_or_bridge(const struct device_node *np,
                                struct drm_panel **panel,
                                struct drm_bridge **bridge)
 {
-       int ret = -EPROBE_DEFER;
-       struct device_node *remote;
+       struct device_node *node;
+       int ret;
 
        if (!panel && !bridge)
                return -EINVAL;
+
        if (panel)
                *panel = NULL;
-
-       /**
-        * Devices can also be child nodes when we also control that device
-        * through the upstream device (ie, MIPI-DCS for a MIPI-DSI device).
-        *
-        * Lookup for a child node of the given parent that isn't either port
-        * or ports.
-        */
-       for_each_available_child_of_node(np, remote) {
-               if (of_node_name_eq(remote, "port") ||
-                   of_node_name_eq(remote, "ports"))
-                       continue;
-
-               goto of_find_panel_or_bridge;
+       if (bridge)
+               *bridge = NULL;
+
+       /* Check for a graph on the device node first. */
+       if (of_graph_is_present(np)) {
+               node = of_graph_get_remote_node(np, port, endpoint);
+               if (node) {
+                       ret = find_panel_or_bridge(node, panel, bridge);
+                       of_node_put(node);
+
+                       if (!ret)
+                               return 0;
+               }
        }
 
-       /*
-        * of_graph_get_remote_node() produces a noisy error message if port
-        * node isn't found and the absence of the port is a legit case here,
-        * so at first we silently check whether graph presents in the
-        * device-tree node.
-        */
-       if (!of_graph_is_present(np))
-               return -ENODEV;
-
-       remote = of_graph_get_remote_node(np, port, endpoint);
-
-of_find_panel_or_bridge:
-       if (!remote)
-               return -ENODEV;
+       /* Otherwise check for any child node other than port/ports. */
+       for_each_available_child_of_node(np, node) {
+               if (of_node_name_eq(node, "port") ||
+                   of_node_name_eq(node, "ports"))
+                       continue;
 
-       if (panel) {
-               *panel = of_drm_find_panel(remote);
-               if (!IS_ERR(*panel))
-                       ret = 0;
-               else
-                       *panel = NULL;
-       }
-
-       /* No panel found yet, check for a bridge next. */
-       if (bridge) {
-               if (ret) {
-                       *bridge = of_drm_find_bridge(remote);
-                       if (*bridge)
-                               ret = 0;
-               } else {
-                       *bridge = NULL;
-               }
+               ret = find_panel_or_bridge(node, panel, bridge);
+               of_node_put(node);
 
+               /* Stop at the first found occurrence. */
+               if (!ret)
+                       return 0;
        }
 
-       of_node_put(remote);
-       return ret;
+       return -EPROBE_DEFER;
 }
 EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);