[media] uvcvideo: Fix crash when linking entities

[pandora-kernel.git] / drivers / media / video / uvc / uvc_entity.c

diff --git a/drivers/media/video/uvc/uvc_entity.c b/drivers/media/video/uvc/uvc_entity.c
index c3ab0c8..29e2399 100644 (file)
--- a/drivers/media/video/uvc/uvc_entity.c
+++ b/drivers/media/video/uvc/uvc_entity.c
@@ -27,14 +27,20 @@ static int uvc_mc_register_entity(struct uvc_video_chain *chain,
        struct uvc_entity *entity)
 {
        const u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
-       struct uvc_entity *remote;
+       struct media_entity *sink;
        unsigned int i;
-       u8 remote_pad;
-       int ret = 0;
+       int ret;
+
+       sink = (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
+            ? (entity->vdev ? &entity->vdev->entity : NULL)
+            : &entity->subdev.entity;
+       if (sink == NULL)
+               return 0;
 
        for (i = 0; i < entity->num_pads; ++i) {
                struct media_entity *source;
-               struct media_entity *sink;
+               struct uvc_entity *remote;
+               u8 remote_pad;
 
                if (!(entity->pads[i].flags & MEDIA_PAD_FL_SINK))
                        continue;
@@ -44,9 +50,10 @@ static int uvc_mc_register_entity(struct uvc_video_chain *chain,
                        return -EINVAL;
 
                source = (UVC_ENTITY_TYPE(remote) == UVC_TT_STREAMING)
-                      ? &remote->vdev->entity : &remote->subdev.entity;
-               sink = (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
-                    ? &entity->vdev->entity : &entity->subdev.entity;
+                      ? (remote->vdev ? &remote->vdev->entity : NULL)
+                      : &remote->subdev.entity;
+               if (source == NULL)
+                       continue;
 
                remote_pad = remote->num_pads - 1;
                ret = media_entity_create_link(source, remote_pad,
@@ -55,11 +62,10 @@ static int uvc_mc_register_entity(struct uvc_video_chain *chain,
                        return ret;
        }
 
-       if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING)
-               ret = v4l2_device_register_subdev(&chain->dev->vdev,
-                                                 &entity->subdev);
+       if (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
+               return 0;
 
-       return ret;
+       return v4l2_device_register_subdev(&chain->dev->vdev, &entity->subdev);
 }
 
 static struct v4l2_subdev_ops uvc_subdev_ops = {
@@ -84,9 +90,11 @@ static int uvc_mc_init_entity(struct uvc_entity *entity)
 
                ret = media_entity_init(&entity->subdev.entity,
                                        entity->num_pads, entity->pads, 0);
-       } else
+       } else if (entity->vdev != NULL) {
                ret = media_entity_init(&entity->vdev->entity,
                                        entity->num_pads, entity->pads, 0);
+       } else
+               ret = 0;
 
        return ret;
 }