media: videobuf2-core: Rework and rename helper for request buffer count

The helper indicating whether buffers are associated with the request is
reworked and renamed to return the number of associated buffer objects.

This is useful for drivers that need to check how many buffers are in
the request to validate it.

Existing users of the helper don't need particular adaptation since the
meaning of zero/non-zero remains consistent.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/common/videobuf2/videobuf2-core.c

@@ -1368,23 +1368,21 @@ bool vb2_request_object_is_buffer(struct media_request_object *obj)
 }
 EXPORT_SYMBOL_GPL(vb2_request_object_is_buffer);
 
-bool vb2_request_has_buffers(struct media_request *req)
+unsigned int vb2_request_buffer_cnt(struct media_request *req)
 {
 	struct media_request_object *obj;
 	unsigned long flags;
-	bool has_buffers = false;
+	unsigned int buffer_cnt = 0;
 
 	spin_lock_irqsave(&req->lock, flags);
-	list_for_each_entry(obj, &req->objects, list) {
-		if (vb2_request_object_is_buffer(obj)) {
-			has_buffers = true;
-			break;
-		}
-	}
+	list_for_each_entry(obj, &req->objects, list)
+		if (vb2_request_object_is_buffer(obj))
+			buffer_cnt++;
 	spin_unlock_irqrestore(&req->lock, flags);
-	return has_buffers;
+
+	return buffer_cnt;
 }
-EXPORT_SYMBOL_GPL(vb2_request_has_buffers);
+EXPORT_SYMBOL_GPL(vb2_request_buffer_cnt);
 
 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
 {

drivers/media/common/videobuf2/videobuf2-v4l2.c

@@ -1139,7 +1139,7 @@ int vb2_request_validate(struct media_request *req)
 	struct media_request_object *obj;
 	int ret = 0;
 
-	if (!vb2_request_has_buffers(req))
+	if (!vb2_request_buffer_cnt(req))
 		return -ENOENT;
 
 	list_for_each_entry(obj, &req->objects, list) {

include/media/videobuf2-core.h

@@ -1191,10 +1191,10 @@ int vb2_verify_memory_type(struct vb2_queue *q,
 bool vb2_request_object_is_buffer(struct media_request_object *obj);
 
 /**
- * vb2_request_has_buffers() - return true if the request contains buffers
+ * vb2_request_buffer_cnt() - return the number of buffers in the request
  *
  * @req:	the request.
  */
-bool vb2_request_has_buffers(struct media_request *req);
+unsigned int vb2_request_buffer_cnt(struct media_request *req);
 
 #endif /* _MEDIA_VIDEOBUF2_CORE_H */