[media] videobuf2-core: Replace BUG_ON and return an error at vb2_queue_init()

This replaces BUG_ON() calls with WARN_ON(), and returns
EINVAL if some parameter is NULL, as suggested by Jonathan and Mauro.
The BUG_ON() call is too drastic to be used in this case.
See the full discussion here:
http://www.spinics.net/lists/linux-media/msg52462.html

Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 11 insertions, 8 deletions

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 59ed5223393b..e6a26b433e87 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1738,14 +1738,17 @@ EXPORT_SYMBOL_GPL(vb2_poll);
  */
 int vb2_queue_init(struct vb2_queue *q)
 {
-        BUG_ON(!q);
-        BUG_ON(!q->ops);
-        BUG_ON(!q->mem_ops);
-        BUG_ON(!q->type);
-        BUG_ON(!q->io_modes);
-
-        BUG_ON(!q->ops->queue_setup);
-        BUG_ON(!q->ops->buf_queue);
+        /*
+         * Sanity check
+         */
+        if (WARN_ON(!q)                   ||
+            WARN_ON(!q->ops)              ||
+            WARN_ON(!q->mem_ops)          ||
+            WARN_ON(!q->type)             ||
+            WARN_ON(!q->io_modes)         ||
+            WARN_ON(!q->ops->queue_setup) ||
+            WARN_ON(!q->ops->buf_queue))
+                return -EINVAL;
 
         INIT_LIST_HEAD(&q->queued_list);
         INIT_LIST_HEAD(&q->done_list);