Hi Michael,
On Mon, May 31, 2021 at 12:30:41AM +0200, Michael Grzeschik wrote:
> With usb3 we handle much more requests. It only enables the interrupt on
s/much/many/
> every quarter of the allocated requests. This patch decreases the
> interrupt load.
The last two sentences might be better combined, like:
"Decrease the interrupt load by only enabling the interrupt every
quarter of the allocated requests."
>
> Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
Other than that, looks good to me.
Reviewed-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx>
> ---
> drivers/usb/gadget/function/uvc.h | 2 ++
> drivers/usb/gadget/function/uvc_video.c | 12 ++++++++++++
> 2 files changed, 14 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
> index c1f06d9df5820..5a76e9351b530 100644
> --- a/drivers/usb/gadget/function/uvc.h
> +++ b/drivers/usb/gadget/function/uvc.h
> @@ -101,6 +101,8 @@ struct uvc_video {
> struct list_head req_free;
> spinlock_t req_lock;
>
> + int req_int_count;
> +
> void (*encode) (struct usb_request *req, struct uvc_video *video,
> struct uvc_buffer *buf);
>
> diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
> index 240d361a45a44..66754687ce217 100644
> --- a/drivers/usb/gadget/function/uvc_video.c
> +++ b/drivers/usb/gadget/function/uvc_video.c
> @@ -357,6 +357,16 @@ static void uvcg_video_pump(struct work_struct *work)
>
> video->encode(req, video, buf);
>
> + if (list_empty(&video->req_free) ||
> + (buf->state == UVC_BUF_STATE_DONE) ||
> + (!(video->req_int_count %
> + DIV_ROUND_UP(video->uvc_num_requests, 4)))) {
> + video->req_int_count = 0;
> + req->no_interrupt = 0;
> + } else {
> + req->no_interrupt = 1;
> + }
> +
> /* Queue the USB request */
> ret = uvcg_video_ep_queue(video, req);
> spin_unlock_irqrestore(&queue->irqlock, flags);
> @@ -365,6 +375,7 @@ static void uvcg_video_pump(struct work_struct *work)
> uvcg_queue_cancel(queue, 0);
> break;
> }
> + video->req_int_count++;
> }
>
> spin_lock_irqsave(&video->req_lock, flags);
> @@ -437,6 +448,7 @@ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
> video->width = 320;
> video->height = 240;
> video->imagesize = 320 * 240 * 2;
> + video->req_int_count = 0;
>
> /* Initialize the video buffers queue. */
> uvcg_queue_init(uvc->v4l2_dev.dev, &video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT,
> --
> 2.29.2
>
