There are some issues to handle frame throughput with camera devices
Using devices:
- Logitech Webcam
- Intel(R) RealSense(TM) Depth Camera
To improve efficiency, and maximise throughput,
use dynamic allocation for uvc_copy_op.
Change from struct uvc_copy_op copy_operations[UVC_MAX_PACKETS];
to struct uvc_copy_op *copy_operations;
Now, only tested bulk video options.
On test device & own debug log to check frame duration(us),
refer to test result the below:
Use copy_operations[UVC_MAX_PACKETS]
[UVC] Check time duration(us) : 64732 / 66000
[UVC] Check time duration(us) : 67452 / 66000
[UVC] Check time duration(us) : 67413 / 66000
[UVC] Check time duration(us) : 66713 / 66000
[UVC] Check time duration(us) : 67967 / 66000
Use *copy_operations
[UVC] Check time duration(us) : 30804 / 66000
[UVC] Check time duration(us) : 38642 / 66000
[UVC] Check time duration(us) : 26011 / 66000
[UVC] Check time duration(us) : 30116 / 66000
[UVC] Check time duration(us) : 29265 / 66000
Signed-off-by: Kyeongdon Kim <kyeongdon.kim@xxxxxxx>
---
drivers/media/usb/uvc/uvc_video.c | 52 ++++++++++++++++++++++++++++++++++++---
drivers/media/usb/uvc/uvcvideo.h | 3 ++-
2 files changed, 51 insertions(+), 4 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index e164646..32bc98e 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1614,6 +1614,33 @@ static void uvc_video_complete(struct urb *urb)
queue_work(stream->async_wq, &uvc_urb->work);
}
+static void uvc_free_urb_cop(struct uvc_streaming *stream)
+{
+ for_each_uvc_urb(uvc_urb, stream) {
+ if (uvc_urb->copy_operations) {
+ kfree(uvc_urb->copy_operations);
+ uvc_urb->copy_operations = NULL;
+ }
+ }
+}
+
+static int uvc_alloc_urb_cop(struct uvc_streaming *stream, gfp_t gfp_flags)
+{
+ int max_packet = stream->urb_max_packets;
+
+ for_each_uvc_urb(uvc_urb, stream) {
+ uvc_urb->copy_operations
+ = kcalloc(max_packet, sizeof(struct uvc_copy_op), gfp_flags);
+ if (uvc_urb->copy_operations == NULL)
+ goto error;
+ }
+ return 0;
+error:
+ uvc_free_urb_cop(stream);
+
+ return -ENOMEM;
+}
+
/*
* Free transfer buffers.
*/
@@ -1687,8 +1714,8 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
* payloads across multiple URBs.
*/
npackets = DIV_ROUND_UP(size, psize);
- if (npackets > UVC_MAX_PACKETS)
- npackets = UVC_MAX_PACKETS;
+ if (npackets > stream->urb_max_packets)
+ npackets = stream->urb_max_packets;
/* Retry allocations until one succeed. */
for (; npackets > 1; npackets /= 2) {
@@ -1744,8 +1771,10 @@ static void uvc_video_stop_transfer(struct uvc_streaming *stream,
uvc_urb->urb = NULL;
}
- if (free_buffers)
+ if (free_buffers) {
uvc_free_urb_buffers(stream);
+ uvc_free_urb_cop(stream);
+ }
}
/*
@@ -1790,10 +1819,18 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
psize = uvc_endpoint_max_bpi(stream->dev->udev, ep);
size = stream->ctrl.dwMaxVideoFrameSize;
+ stream->urb_max_packets = UVC_MAX_PACKETS;
+
npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
if (npackets == 0)
return -ENOMEM;
+ if (uvc_alloc_urb_cop(stream, gfp_flags) != 0) {
+ uvc_dbg(stream->dev, VIDEO,
+ "Failed to init URBs copy operations.\n");
+ return -ENOMEM;
+ }
+
size = npackets * psize;
for_each_uvc_urb(uvc_urb, stream) {
@@ -1842,11 +1879,18 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
psize = usb_endpoint_maxp(&ep->desc);
size = stream->ctrl.dwMaxPayloadTransferSize;
stream->bulk.max_payload_size = size;
+ stream->urb_max_packets = DIV_ROUND_UP(size, psize);
npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
if (npackets == 0)
return -ENOMEM;
+ if (uvc_alloc_urb_cop(stream, gfp_flags) != 0) {
+ uvc_dbg(stream->dev, VIDEO,
+ "Failed to init URBs copy operations.\n");
+ return -ENOMEM;
+ }
+
size = npackets * psize;
if (usb_endpoint_dir_in(&ep->desc))
@@ -2147,6 +2191,8 @@ int uvc_video_init(struct uvc_streaming *stream)
}
}
+ stream->urb_max_packets = UVC_MAX_PACKETS;
+
/* Prepare asynchronous work items. */
for_each_uvc_urb(uvc_urb, stream)
INIT_WORK(&uvc_urb->work, uvc_video_copy_data_work);
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index cce5e38..00cf6c9 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -561,7 +561,7 @@ struct uvc_urb {
struct sg_table *sgt;
unsigned int async_operations;
- struct uvc_copy_op copy_operations[UVC_MAX_PACKETS];
+ struct uvc_copy_op *copy_operations;
struct work_struct work;
};
@@ -616,6 +616,7 @@ struct uvc_streaming {
struct uvc_urb uvc_urb[UVC_URBS];
unsigned int urb_size;
+ unsigned int urb_max_packets;
u32 sequence;
u8 last_fid;
--
2.10.2
