[media] vb2: add is_unordered callback for drivers

Explicit synchronization benefits a lot from ordered queues, they fit
better in a pipeline with DRM for example so create a opt-in way for
drivers notify videobuf2 that the queue is unordered.

Drivers don't need implement it if the queue is ordered.

v2:	- improve comments for is_unordered flag (Hans)

v3:	- make it bool (Hans)
	- create vb2_ops_set_unordered() helper

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Change-Id: I519c8576f2fd1b83e60a4da40c169b16b86ef825
Signed-off-by: Janghyuck Kim <janghyuck.kim@samsung.com>

diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
index 466de62ad1e36c8738a354e67eda040e55d00578..5f4a57d10f071426d28dd673f2d31af8ac351459 100644 (file)
--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -960,6 +960,12 @@ void vb2_ops_wait_finish(struct vb2_queue *vq)
 }
 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
 
+bool vb2_ops_set_unordered(struct vb2_queue *q)
+{
+       return true;
+}
+EXPORT_SYMBOL_GPL(vb2_ops_set_unordered);
+
 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
 MODULE_LICENSE("GPL");

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index ef9b64398c8c9586f741867f13e20e7a157fd16c..87a7f3fec23d8d2be02ffee69f3444f8e779bacf 100644 (file)
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -368,6 +368,10 @@ struct vb2_buffer {
  *                     callback by calling vb2_buffer_done() with either
  *                     %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
  *                     vb2_wait_for_all_buffers() function
+ * @is_unordered:      tell if the queue is unordered, i.e. buffers can be
+ *                     dequeued in a different order from how they were queued.
+ *                     The default is assumed to be ordered and this function
+ *                     only needs to be implemented for unordered queues.
  * @buf_queue:         passes buffer vb to the driver; driver may start
  *                     hardware operation on this buffer; driver should give
  *                     the buffer back by calling vb2_buffer_done() function;
@@ -391,6 +395,7 @@ struct vb2_ops {
 
        int (*start_streaming)(struct vb2_queue *q, unsigned int count);
        void (*stop_streaming)(struct vb2_queue *q);
+       bool (*is_unordered)(struct vb2_queue *q);
 
        void (*buf_queue)(struct vb2_buffer *vb);
 };
@@ -564,6 +569,7 @@ struct vb2_queue {
        u32                             cnt_wait_finish;
        u32                             cnt_start_streaming;
        u32                             cnt_stop_streaming;
+       u32                             cnt_is_unordered;
 #endif
 };
 

diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index 64bc7dfaddde41465df11cd89a0b97bb88be2427..1922536c9da6349caf36e9cac990b9bb72496eca 100644 (file)
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -288,4 +288,14 @@ void vb2_ops_wait_prepare(struct vb2_queue *vq);
  */
 void vb2_ops_wait_finish(struct vb2_queue *vq);
 
+/**
+ * vb2_ops_set_unordered - helper function to mark queue as unordered
+ *
+ * @vq: pointer to &struct vb2_queue
+ *
+ * This helper just return true to notify that the driver can't deal with
+ * ordered queues.
+ */
+bool vb2_ops_set_unordered(struct vb2_queue *q);
+
 #endif /* _MEDIA_VIDEOBUF2_V4L2_H */