diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index cb35687b11e7e..55d796f5f5e8d 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -71,6 +71,9 @@ extern unsigned int uvc_gadget_trace_param; #define UVCG_REQUEST_HEADER_LEN 12 +#define UVCG_REQ_MAX_INT_COUNT 16 +#define UVCG_REQ_MAX_ZERO_COUNT (2 * UVCG_REQ_MAX_INT_COUNT) + /* ------------------------------------------------------------------------ * Structures */ @@ -91,6 +94,8 @@ struct uvc_video { struct work_struct pump; struct workqueue_struct *async_wq; + atomic_t queued; + /* Frame parameters */ u8 bpp; u32 fcc; diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index 002bf724d8025..c041873cf8560 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -269,6 +269,8 @@ static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req) } } + atomic_inc(&video->queued); + return ret; } @@ -304,7 +306,7 @@ static int uvcg_video_usb_req_queue(struct uvc_video *video, */ if (list_empty(&video->req_free) || ureq->last_buf || !(video->req_int_count % - DIV_ROUND_UP(video->uvc_num_requests, 4))) { + min(DIV_ROUND_UP(video->uvc_num_requests, 4), UVCG_REQ_MAX_INT_COUNT))) { video->req_int_count = 0; req->no_interrupt = 0; } else { @@ -379,6 +381,7 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) int ret = 0; spin_lock_irqsave(&video->req_lock, flags); + atomic_dec(&video->queued); if (!video->is_enabled) { /* * When is_enabled is false, uvcg_video_disable() ensures @@ -466,6 +469,16 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) * happen. */ queue_work(video->async_wq, &video->pump); + } else if (atomic_read(&video->queued) > UVCG_REQ_MAX_ZERO_COUNT) { + list_add_tail(&to_queue->list, &video->req_free); + /* + * There is a new free request - wake up the pump. + */ + queue_work(video->async_wq, &video->pump); + + spin_unlock_irqrestore(&video->req_lock, flags); + + return; } /* * Queue to the endpoint. The actual queueing to ep will @@ -756,6 +769,8 @@ int uvcg_video_enable(struct uvc_video *video) video->req_int_count = 0; + atomic_set(&video->queued, 0); + uvc_video_ep_queue_initial_requests(video); queue_work(video->async_wq, &video->pump);