[PATCH 1/3] vb2: add requires_requests bit for stateless codecs

[Hans Verkuil <hverkuil-cisco@xs4all.nl>]

Stateless codecs require the use of the Request API as opposed of it
being optional.

So add a bit to indicate this and let vb2 check for this.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
---
 drivers/media/common/videobuf2/videobuf2-core.c | 5 ++++-
 drivers/media/common/videobuf2/videobuf2-v4l2.c | 6 ++++++
 include/media/videobuf2-core.h                  | 3 +++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index e07b6bdb6982..2c12b331ac5a 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -1516,7 +1516,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
 
 	if ((req && q->uses_qbuf) ||
 	    (!req && vb->state != VB2_BUF_STATE_IN_REQUEST &&
-	     q->uses_requests)) {
+	     (q->uses_requests || q->requires_requests))) {
 		dprintk(1, "queue in wrong mode (qbuf vs requests)\n");
 		return -EBUSY;
 	}
@@ -2245,6 +2245,9 @@ int vb2_core_queue_init(struct vb2_queue *q)
 	    WARN_ON(!q->ops->buf_queue))
 		return -EINVAL;
 
+	if (WARN_ON(q->requires_requests && !q->supports_requests))
+		return -EINVAL;
+
 	INIT_LIST_HEAD(&q->queued_list);
 	INIT_LIST_HEAD(&q->done_list);
 	spin_lock_init(&q->done_lock);
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 3aeaea3af42a..8b15b7762c56 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -385,6 +385,10 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
 			dprintk(1, "%s: queue uses requests\n", opname);
 			return -EBUSY;
 		}
+		if (q->requires_requests) {
+			dprintk(1, "%s: queue requires requests\n", opname);
+			return -EACCES;
+		}
 		return 0;
 	} else if (!q->supports_requests) {
 		dprintk(1, "%s: queue does not support requests\n", opname);
@@ -657,6 +661,8 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
 #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
 	if (q->supports_requests)
 		*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
+	if (q->requires_requests)
+		*caps |= V4L2_BUF_CAP_REQUIRES_REQUESTS;
 #endif
 }
 
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 4849b865b908..8e4c16446a88 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -480,6 +480,8 @@ struct vb2_buf_ops {
  *              has not been called. This is a vb1 idiom that has been adopted
  *              also by vb2.
  * @supports_requests: this queue supports the Request API.
+ * @requires_requests: this queue requires the Request API. If this is set to 1,
+ *		then supports_requests must be set to 1 as well.
  * @uses_qbuf:	qbuf was used directly for this queue. Set to 1 the first
  *		time this is called. Set to 0 when the queue is canceled.
  *		If this is 1, then you cannot queue buffers from a request.
@@ -554,6 +556,7 @@ struct vb2_queue {
 	unsigned			allow_zero_bytesused:1;
 	unsigned		   quirk_poll_must_check_waiting_for_buffers:1;
 	unsigned			supports_requests:1;
+	unsigned			requires_requests:1;
 	unsigned			uses_qbuf:1;
 	unsigned			uses_requests:1;
 
-- 
2.20.1