[PATCH] media: uvcvideo: Add a stream backpointer in uvc_video_queue

[Ricardo Ribalda]

It is less prone to errors if we add a backpointer to stream from
struct uvc_video_queue.

Refactor the code.

Suggested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
Tested in real hardware with yavta:
(console A) # yavta -c /dev/video1 
(console B) # yavta -c /dev/video0
It would be great if we add it as a follow-up patch to the already
merged series.

Thanks!

 drivers/media/usb/uvc/uvc_driver.c |  2 +-
 drivers/media/usb/uvc/uvc_isight.c |  3 +--
 drivers/media/usb/uvc/uvc_queue.c  | 15 ++++++++-------
 drivers/media/usb/uvc/uvcvideo.h   | 12 +++---------
 4 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index b0ca81d924b6..017b1f4ae3ab 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -2033,7 +2033,7 @@ int uvc_register_video_device(struct uvc_device *dev,
 	int ret;
 
 	/* Initialize the video buffers queue. */
-	ret = uvc_queue_init(queue, type);
+	ret = uvc_queue_init(stream, queue, type);
 	if (ret)
 		return ret;
 
diff --git a/drivers/media/usb/uvc/uvc_isight.c b/drivers/media/usb/uvc/uvc_isight.c
index ea9dc31dfbad..bb3e13c0d5a6 100644
--- a/drivers/media/usb/uvc/uvc_isight.c
+++ b/drivers/media/usb/uvc/uvc_isight.c
@@ -41,8 +41,7 @@ static int isight_decode(struct uvc_video_queue *queue, struct uvc_buffer *buf,
 		0xde, 0xad, 0xfa, 0xce
 	};
 
-	struct uvc_streaming *stream = uvc_queue_to_stream(queue,
-						V4L2_BUF_TYPE_VIDEO_CAPTURE);
+	struct uvc_streaming *stream = queue->stream;
 	unsigned int maxlen, nbytes;
 	u8 *mem;
 	int is_header = 0;
diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index 89206f761006..3c002c8f442f 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -78,7 +78,7 @@ static int uvc_queue_setup(struct vb2_queue *vq,
 			   unsigned int sizes[], struct device *alloc_devs[])
 {
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
-	struct uvc_streaming *stream = uvc_queue_to_stream(queue, vq->type);
+	struct uvc_streaming *stream = queue->stream;
 	unsigned int size;
 
 	switch (vq->type) {
@@ -112,7 +112,7 @@ static int uvc_buffer_prepare(struct vb2_buffer *vb)
 
 	if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
 	    vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
-		uvc_dbg(uvc_queue_to_stream(queue, vb->type)->dev, CAPTURE,
+		uvc_dbg(queue->stream->dev, CAPTURE,
 			"[E] Bytes used out of bounds\n");
 		return -EINVAL;
 	}
@@ -159,17 +159,16 @@ static void uvc_buffer_finish(struct vb2_buffer *vb)
 {
 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
-	struct uvc_streaming *stream = uvc_queue_to_stream(queue, vb->type);
 	struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf);
 
 	if (vb->state == VB2_BUF_STATE_DONE)
-		uvc_video_clock_update(stream, vbuf, buf);
+		uvc_video_clock_update(queue->stream, vbuf, buf);
 }
 
 static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
 {
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
-	struct uvc_streaming *stream = uvc_queue_to_stream(queue, vq->type);
+	struct uvc_streaming *stream = queue->stream;
 	int ret;
 
 	lockdep_assert_irqs_enabled();
@@ -196,7 +195,7 @@ static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
 static void uvc_stop_streaming_video(struct vb2_queue *vq)
 {
 	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
-	struct uvc_streaming *stream = uvc_queue_to_stream(queue, vq->type);
+	struct uvc_streaming *stream = queue->stream;
 
 	lockdep_assert_irqs_enabled();
 
@@ -237,10 +236,12 @@ static const struct vb2_ops uvc_meta_queue_qops = {
 	.stop_streaming = uvc_stop_streaming_meta,
 };
 
-int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type)
+int uvc_queue_init(struct uvc_streaming *stream, struct uvc_video_queue *queue,
+		   enum v4l2_buf_type type)
 {
 	int ret;
 
+	queue->stream = stream;
 	queue->queue.type = type;
 	queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
 	queue->queue.drv_priv = queue;
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 5ba698d2a23d..0a0c01b2420f 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -331,6 +331,7 @@ struct uvc_buffer {
 #define UVC_QUEUE_DISCONNECTED		(1 << 0)
 
 struct uvc_video_queue {
+	struct uvc_streaming *stream;
 	struct video_device vdev;
 	struct vb2_queue queue;
 	struct mutex mutex;			/*
@@ -692,7 +693,8 @@ do {									\
 struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id);
 
 /* Video buffers queue management. */
-int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type);
+int uvc_queue_init(struct uvc_streaming *stream, struct uvc_video_queue *queue,
+		   enum v4l2_buf_type type);
 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect);
 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
 					 struct uvc_buffer *buf);
@@ -703,14 +705,6 @@ static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
 	return vb2_is_streaming(&queue->queue);
 }
 
-static inline struct uvc_streaming *
-uvc_queue_to_stream(struct uvc_video_queue *queue, unsigned int type)
-{
-	if (type == V4L2_BUF_TYPE_META_CAPTURE)
-		return container_of(queue, struct uvc_streaming, meta.queue);
-	return container_of(queue, struct uvc_streaming, queue);
-}
-
 /* V4L2 interface */
 extern const struct v4l2_ioctl_ops uvc_ioctl_ops;
 extern const struct v4l2_file_operations uvc_fops;
-- 
2.53.0.983.g0bb29b3bc5-goog