Calling uvcg_complete_buffer() from uvc_video_encode_isoc() sometimes
causes the final isoc packet for a video frame to be delayed long
enough to cause the USB controller to drop it. The first isoc packet
of the next video frame is then received by the host, which interprets
the toggled FID bit correctly such that the stream continues without
interruption, but the first frame will be missing the last isoc
packet's worth of bytes.
To fix the issue delay the call to uvcg_complete_buffer() until the
usb_request's .complete() callback, as already happens when the data
is encoded via uvc_video_encode_isoc_sg().
Signed-off-by: Daniel Scally <dan.scally@xxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/function/uvc_video.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index c00ce0e91f5d..041819a655ed 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -194,6 +194,7 @@ static void
uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
struct uvc_buffer *buf)
{
+ struct uvc_request *ureq = req->context;
void *mem = req->buf;
int len = video->req_size;
int ret;
@@ -213,7 +214,7 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
video->queue.buf_used = 0;
buf->state = UVC_BUF_STATE_DONE;
list_del(&buf->queue);
- uvcg_complete_buffer(&video->queue, buf);
+ ureq->last_buf = buf;
video->fid ^= UVC_STREAM_FID;
}
}
--
2.34.1
