1 files changed, 21 insertions, 6 deletions

diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
index 1fe122461298..2763a5ec845b 100644
--- a/drivers/gpu/drm/drm_of.c
+++ b/drivers/gpu/drm/drm_of.c
@@ -9,21 +9,28 @@
 #include <drm/drm_panel.h>
 #include <drm/drm_of.h>
 
+/**
+ * DOC: overview
+ *
+ * A set of helper functions to aid DRM drivers in parsing standard DT
+ * properties.
+ */
+
 static void drm_release_of(struct device *dev, void *data)
 {
         of_node_put(data);
 }
 
 /**
- * drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
+ * drm_of_crtc_port_mask - find the mask of a registered CRTC by port OF node
  * @dev: DRM device
  * @port: port OF node
  *
  * Given a port OF node, return the possible mask of the corresponding
  * CRTC within a device's list of CRTCs.  Returns zero if not found.
  */
-static uint32_t drm_crtc_port_mask(struct drm_device *dev,
-                                   struct device_node *port)
+uint32_t drm_of_crtc_port_mask(struct drm_device *dev,
+                            struct device_node *port)
 {
         unsigned int index = 0;
         struct drm_crtc *tmp;
@@ -37,6 +44,7 @@ static uint32_t drm_crtc_port_mask(struct drm_device *dev,
 
         return 0;
 }
+EXPORT_SYMBOL(drm_of_crtc_port_mask);
 
 /**
  * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
@@ -62,7 +70,7 @@ uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
                         return 0;
                 }
 
-                possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
+                possible_crtcs |= drm_of_crtc_port_mask(dev, remote_port);
 
                 of_node_put(remote_port);
         }
@@ -93,7 +101,7 @@ EXPORT_SYMBOL_GPL(drm_of_component_match_add);
  * drm_of_component_probe - Generic probe function for a component based master
  * @dev: master device containing the OF node
  * @compare_of: compare function used for matching components
- * @master_ops: component master ops to be used
+ * @m_ops: component master ops to be used
  *
  * Parse the platform device OF node and bind all the components associated
  * with the master. Interface ports are added before the encoders in order to
@@ -238,10 +246,17 @@ int drm_of_find_panel_or_bridge(const struct device_node *np,
         if (!remote)
                 return -ENODEV;
 
+        if (!of_device_is_available(remote)) {
+                of_node_put(remote);
+                return -ENODEV;
+        }
+
         if (panel) {
                 *panel = of_drm_find_panel(remote);
-                if (*panel)
+                if (!IS_ERR(*panel))
                         ret = 0;
+                else
+                        *panel = NULL;
         }
 
         /* No panel found yet, check for a bridge next. */