1 files changed, 44 insertions, 53 deletions

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index e89fd53a021..6687ac33726 100644
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -1111,6 +1111,43 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
 EXPORT_SYMBOL_GPL(vb2_dqbuf);
 
 /**
+ * __vb2_queue_cancel() - cancel and stop (pause) streaming
+ *
+ * Removes all queued buffers from driver's queue and all buffers queued by
+ * userspace from videobuf's queue. Returns to state after reqbufs.
+ */
+static void __vb2_queue_cancel(struct vb2_queue *q)
+{
+	unsigned int i;
+
+	/*
+	 * Tell driver to stop all transactions and release all queued
+	 * buffers.
+	 */
+	if (q->streaming)
+		call_qop(q, stop_streaming, q);
+	q->streaming = 0;
+
+	/*
+	 * Remove all buffers from videobuf's list...
+	 */
+	INIT_LIST_HEAD(&q->queued_list);
+	/*
+	 * ...and done list; userspace will not receive any buffers it
+	 * has not already dequeued before initiating cancel.
+	 */
+	INIT_LIST_HEAD(&q->done_list);
+	atomic_set(&q->queued_count, 0);
+	wake_up_all(&q->done_wq);
+
+	/*
+	 * Reinitialize all buffers for next use.
+	 */
+	for (i = 0; i < q->num_buffers; ++i)
+		q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED;
+}
+
+/**
  * vb2_streamon - start streaming
  * @q:		videobuf2 queue
  * @type:	type argument passed from userspace to vidioc_streamon handler
@@ -1118,7 +1155,7 @@ EXPORT_SYMBOL_GPL(vb2_dqbuf);
  * Should be called from vidioc_streamon handler of a driver.
  * This function:
  * 1) verifies current state
- * 2) starts streaming and passes any previously queued buffers to the driver
+ * 2) passes any previously queued buffers to the driver and starts streaming
  *
  * The return values from this function are intended to be directly returned
  * from vidioc_streamon handler in the driver.
@@ -1144,75 +1181,29 @@ int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
 	}
 
 	/*
-	 * Cannot start streaming on an OUTPUT device if no buffers have
-	 * been queued yet.
+	 * If any buffers were queued before streamon,
+	 * we can now pass them to driver for processing.
 	 */
-	if (V4L2_TYPE_IS_OUTPUT(q->type)) {
-		if (list_empty(&q->queued_list)) {
-			dprintk(1, "streamon: no output buffers queued\n");
-			return -EINVAL;
-		}
-	}
+	list_for_each_entry(vb, &q->queued_list, queued_entry)
+		__enqueue_in_driver(vb);
 
 	/*
 	 * Let driver notice that streaming state has been enabled.
 	 */
-	ret = call_qop(q, start_streaming, q);
+	ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
 	if (ret) {
 		dprintk(1, "streamon: driver refused to start streaming\n");
+		__vb2_queue_cancel(q);
 		return ret;
 	}
 
 	q->streaming = 1;
 
-	/*
-	 * If any buffers were queued before streamon,
-	 * we can now pass them to driver for processing.
-	 */
-	list_for_each_entry(vb, &q->queued_list, queued_entry)
-		__enqueue_in_driver(vb);
-
 	dprintk(3, "Streamon successful\n");
 	return 0;
 }
 EXPORT_SYMBOL_GPL(vb2_streamon);
 
-/**
- * __vb2_queue_cancel() - cancel and stop (pause) streaming
- *
- * Removes all queued buffers from driver's queue and all buffers queued by
- * userspace from videobuf's queue. Returns to state after reqbufs.
- */
-static void __vb2_queue_cancel(struct vb2_queue *q)
-{
-	unsigned int i;
-
-	/*
-	 * Tell driver to stop all transactions and release all queued
-	 * buffers.
-	 */
-	if (q->streaming)
-		call_qop(q, stop_streaming, q);
-	q->streaming = 0;
-
-	/*
-	 * Remove all buffers from videobuf's list...
-	 */
-	INIT_LIST_HEAD(&q->queued_list);
-	/*
-	 * ...and done list; userspace will not receive any buffers it
-	 * has not already dequeued before initiating cancel.
-	 */
-	INIT_LIST_HEAD(&q->done_list);
-	atomic_set(&q->queued_count, 0);
-	wake_up_all(&q->done_wq);
-
-	/*
-	 * Reinitialize all buffers for next use.
-	 */
-	for (i = 0; i < q->num_buffers; ++i)
-		q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED;
-}
 
 /**
  * vb2_streamoff - stop streaming