2 files changed, 10 insertions, 9 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 89e38392509c..02281d13505f 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -2374,13 +2374,20 @@ __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
 	struct vb2_buffer *vb = NULL;
 	unsigned long flags;
 
+	/*
+	 * poll_wait() MUST be called on the first invocation on all the
+	 * potential queues of interest, even if we are not interested in their
+	 * events during this first call. Failure to do so will result in
+	 * queue's events to be ignored because the poll_table won't be capable
+	 * of adding new wait queues thereafter.
+	 */
+	poll_wait(file, &q->done_wq, wait);
+
 	if (!q->is_output && !(req_events & (EPOLLIN | EPOLLRDNORM)))
 		return 0;
 	if (q->is_output && !(req_events & (EPOLLOUT | EPOLLWRNORM)))
 		return 0;
 
-	poll_wait(file, &q->done_wq, wait);
-
 	/*
 	 * Start file I/O emulator only if streaming API has not been used yet.
 	 */
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 96d3b2b2aa31..7e96f67c60ba 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -118,8 +118,7 @@ static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 				return -EINVAL;
 		}
 	} else {
-		length = (b->memory == VB2_MEMORY_USERPTR ||
-			  b->memory == VB2_MEMORY_DMABUF)
+		length = (b->memory == VB2_MEMORY_USERPTR)
 			? b->length : vb->planes[0].length;
 
 		if (b->bytesused > length)
@@ -488,11 +487,6 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
 		    !q->ops->buf_out_validate))
 		return -EINVAL;
 
-	if (b->request_fd < 0) {
-		dprintk(q, 1, "%s: request_fd < 0\n", opname);
-		return -EINVAL;
-	}
-
 	req = media_request_get_by_fd(mdev, b->request_fd);
 	if (IS_ERR(req)) {
 		dprintk(q, 1, "%s: invalid request_fd\n", opname);