Compressed formats generate content depending amount of data that is set
in the vb2 buffer by the payload_size. When streaming those formats it
is better to scatter that smaller data over all requests. This patch is
doing that by introducing the calculated req_payload_size which is
updated by each frame. It the uses this amount of data to fill the
isoc requests instead of the video->req_size.
For uncompressed formats it will not make a difference since the payload
size will be equal to the imagesize. Therefore the code will have no
effecta as req_payload_size will be equal to req_size.
Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
---
v4 -> v5:
- keep using req_size instead of len in encode_isoc_sg to be more
explicit
- using new initialized variable reqs_per_frame instead of two
calculations
- reordered this patch in the series
v1 -> v4: -
---
drivers/usb/gadget/function/uvc.h | 2 ++
drivers/usb/gadget/function/uvc_queue.c | 10 ++++++++--
drivers/usb/gadget/function/uvc_queue.h | 2 ++
drivers/usb/gadget/function/uvc_video.c | 15 ++++++++-------
4 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index 099038f1088ef..bedb4ef42864f 100644
--- a/drivers/usb/gadget/function/uvc.h
+++ b/drivers/usb/gadget/function/uvc.h
@@ -110,6 +110,8 @@ struct uvc_video {
unsigned int uvc_num_requests;
+ unsigned int reqs_per_frame;
+
/* Requests */
bool is_enabled; /* tracks whether video stream is enabled */
unsigned int req_size;
diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
index 731e3b9d21acc..6757a4e25a743 100644
--- a/drivers/usb/gadget/function/uvc_queue.c
+++ b/drivers/usb/gadget/function/uvc_queue.c
@@ -58,6 +58,7 @@ static int uvc_queue_setup(struct vb2_queue *vq,
static int uvc_buffer_prepare(struct vb2_buffer *vb)
{
struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+ struct uvc_video *video = container_of(queue, struct uvc_video, queue);
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
@@ -78,10 +79,15 @@ static int uvc_buffer_prepare(struct vb2_buffer *vb)
buf->mem = vb2_plane_vaddr(vb, 0);
}
buf->length = vb2_plane_size(vb, 0);
- if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+ if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
buf->bytesused = 0;
- else
+ } else {
buf->bytesused = vb2_get_plane_payload(vb, 0);
+ buf->req_payload_size =
+ DIV_ROUND_UP(buf->bytesused +
+ (video->reqs_per_frame * UVCG_REQUEST_HEADER_LEN),
+ video->reqs_per_frame);
+ }
return 0;
}
diff --git a/drivers/usb/gadget/function/uvc_queue.h b/drivers/usb/gadget/function/uvc_queue.h
index 41f87b917f6bc..b54becc570a38 100644
--- a/drivers/usb/gadget/function/uvc_queue.h
+++ b/drivers/usb/gadget/function/uvc_queue.h
@@ -39,6 +39,8 @@ struct uvc_buffer {
unsigned int offset;
unsigned int length;
unsigned int bytesused;
+ /* req_payload_size: only used with isoc */
+ unsigned int req_payload_size;
};
#define UVC_QUEUE_DISCONNECTED (1 << 0)
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index 4efd7585d7541..0287a56fa50ad 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -136,7 +136,7 @@ uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
unsigned int pending = buf->bytesused - video->queue.buf_used;
struct uvc_request *ureq = req->context;
struct scatterlist *sg, *iter;
- unsigned int len = video->req_size;
+ unsigned int len = buf->req_payload_size;
unsigned int sg_left, part = 0;
unsigned int i;
int header_len;
@@ -146,15 +146,15 @@ uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
/* Init the header. */
header_len = uvc_video_encode_header(video, buf, ureq->header,
- video->req_size);
+ buf->req_payload_size);
sg_set_buf(sg, ureq->header, header_len);
len -= header_len;
if (pending <= len)
len = pending;
- req->length = (len == pending) ?
- len + header_len : video->req_size;
+ req->length = (len == pending) ? len + header_len :
+ buf->req_payload_size;
/* Init the pending sgs with payload */
sg = sg_next(sg);
@@ -202,7 +202,7 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
{
void *mem = req->buf;
struct uvc_request *ureq = req->context;
- int len = video->req_size;
+ int len = buf->req_payload_size;
int ret;
/* Add the header. */
@@ -214,7 +214,7 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
ret = uvc_video_encode_data(video, buf, mem, len);
len -= ret;
- req->length = video->req_size - len;
+ req->length = buf->req_payload_size - len;
if (buf->bytesused == video->queue.buf_used ||
video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) {
@@ -504,7 +504,7 @@ uvc_video_prep_requests(struct uvc_video *video)
if (!usb_endpoint_xfer_isoc(video->ep->desc)) {
video->req_size = max_req_size;
- video->uvc_num_requests =
+ video->reqs_per_frame = video->uvc_num_requests =
DIV_ROUND_UP(video->imagesize, max_req_size);
return;
@@ -535,6 +535,7 @@ uvc_video_prep_requests(struct uvc_video *video)
* able to fully encode one frame.
*/
video->uvc_num_requests = nreq + UVCG_REQ_MAX_ZERO_COUNT;
+ video->reqs_per_frame = nreq;
}
static int
--
2.39.5
