diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c index edf0355d712ce..aa6ab666741a9 100644 --- a/drivers/usb/gadget/function/f_uvc.c +++ b/drivers/usb/gadget/function/f_uvc.c @@ -991,6 +991,8 @@ static void uvc_function_unbind(struct usb_configuration *c, uvcg_info(f, "%s()\n", __func__); + kthread_cancel_work_sync(&video->hw_submit); + if (video->async_wq) destroy_workqueue(video->async_wq); diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index 55d796f5f5e8d..4f44a607d9f5c 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -94,6 +94,9 @@ struct uvc_video { struct work_struct pump; struct workqueue_struct *async_wq; + struct kthread_worker *kworker; + struct kthread_work hw_submit; + atomic_t queued; /* Frame parameters */ diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index c041873cf8560..06055959f7165 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -324,50 +324,6 @@ static int uvcg_video_usb_req_queue(struct uvc_video *video, return 0; } -/* - * Must only be called from uvcg_video_enable - since after that we only want to - * queue requests to the endpoint from the uvc_video_complete complete handler. - * This function is needed in order to 'kick start' the flow of requests from - * gadget driver to the usb controller. - */ -static void uvc_video_ep_queue_initial_requests(struct uvc_video *video) -{ - struct usb_request *req = NULL; - unsigned long flags = 0; - unsigned int count = 0; - int ret = 0; - - /* - * We only queue half of the free list since we still want to have - * some free usb_requests in the free list for the video_pump async_wq - * thread to encode uvc buffers into. Otherwise we could get into a - * situation where the free list does not have any usb requests to - * encode into - we always end up queueing 0 length requests to the - * end point. - */ - unsigned int half_list_size = video->uvc_num_requests / 2; - - spin_lock_irqsave(&video->req_lock, flags); - /* - * Take these requests off the free list and queue them all to the - * endpoint. Since we queue 0 length requests with the req_lock held, - * there isn't any 'data' race involved here with the complete handler. - */ - while (count < half_list_size) { - req = list_first_entry(&video->req_free, struct usb_request, - list); - list_del(&req->list); - req->length = 0; - ret = uvcg_video_ep_queue(video, req); - if (ret < 0) { - uvcg_queue_cancel(&video->queue, 0); - break; - } - count++; - } - spin_unlock_irqrestore(&video->req_lock, flags); -} - static void uvc_video_complete(struct usb_ep *ep, struct usb_request *req) { @@ -375,10 +331,7 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) struct uvc_video *video = ureq->video; struct uvc_video_queue *queue = &video->queue; struct uvc_buffer *last_buf; - struct usb_request *to_queue = req; unsigned long flags; - bool is_bulk = video->max_payload_size; - int ret = 0; spin_lock_irqsave(&video->req_lock, flags); atomic_dec(&video->queued); @@ -441,65 +394,85 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req) return; } + list_add_tail(&req->list, &video->req_free); /* - * Here we check whether any request is available in the ready - * list. If it is, queue it to the ep and add the current - * usb_request to the req_free list - for video_pump to fill in. - * Otherwise, just use the current usb_request to queue a 0 - * length request to the ep. Since we always add to the req_free - * list if we dequeue from the ready list, there will never - * be a situation where the req_free list is completely out of - * requests and cannot recover. + * Queue work to the wq as well since it is possible that a + * buffer may not have been completely encoded with the set of + * in-flight usb requests for whih the complete callbacks are + * firing. + * In that case, if we do not queue work to the worker thread, + * the buffer will never be marked as complete - and therefore + * not be returned to userpsace. As a result, + * dequeue -> queue -> dequeue flow of uvc buffers will not + * happen. Since there are is a new free request wake up the pump. */ - to_queue->length = 0; - if (!list_empty(&video->req_ready)) { - to_queue = list_first_entry(&video->req_ready, - struct usb_request, list); - list_del(&to_queue->list); - list_add_tail(&req->list, &video->req_free); - /* - * Queue work to the wq as well since it is possible that a - * buffer may not have been completely encoded with the set of - * in-flight usb requests for whih the complete callbacks are - * firing. - * In that case, if we do not queue work to the worker thread, - * the buffer will never be marked as complete - and therefore - * not be returned to userpsace. As a result, - * dequeue -> queue -> dequeue flow of uvc buffers will not - * 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); + queue_work(video->async_wq, &video->pump); - spin_unlock_irqrestore(&video->req_lock, flags); + spin_unlock_irqrestore(&video->req_lock, flags); - return; - } - /* - * Queue to the endpoint. The actual queueing to ep will - * only happen on one thread - the async_wq for bulk endpoints - * and this thread for isoc endpoints. - */ - ret = uvcg_video_usb_req_queue(video, to_queue, !is_bulk); - if (ret < 0) { + kthread_queue_work(video->kworker, &video->hw_submit); +} + +static void uvcg_video_hw_submit(struct kthread_work *work) +{ + struct uvc_video *video = container_of(work, struct uvc_video, hw_submit); + bool is_bulk = video->max_payload_size; + unsigned long flags; + struct usb_request *req; + int ret = 0; + + while (true) { + if (!video->ep->enabled) + return; + spin_lock_irqsave(&video->req_lock, flags); /* - * Endpoint error, but the stream is still enabled. - * Put request back in req_free for it to be cleaned - * up later. + * Here we check whether any request is available in the ready + * list. If it is, queue it to the ep and add the current + * usb_request to the req_free list - for video_pump to fill in. + * Otherwise, just use the current usb_request to queue a 0 + * length request to the ep. Since we always add to the req_free + * list if we dequeue from the ready list, there will never + * be a situation where the req_free list is completely out of + * requests and cannot recover. */ - list_add_tail(&to_queue->list, &video->req_free); + if (!list_empty(&video->req_ready)) { + req = list_first_entry(&video->req_ready, + struct usb_request, list); + } else { + if (list_empty(&video->req_free) || + (atomic_read(&video->queued) > UVCG_REQ_MAX_ZERO_COUNT)) { + spin_unlock_irqrestore(&video->req_lock, flags); + + return; + } + req = list_first_entry(&video->req_free, struct usb_request, + list); + req->length = 0; + } + list_del(&req->list); + /* - * There is a new free request - wake up the pump. + * Queue to the endpoint. The actual queueing to ep will + * only happen on one thread - the async_wq for bulk endpoints + * and this thread for isoc endpoints. */ - queue_work(video->async_wq, &video->pump); - } + ret = uvcg_video_usb_req_queue(video, req, !is_bulk); + if (ret < 0) { + /* + * Endpoint error, but the stream is still enabled. + * Put request back in req_free for it to be cleaned + * up later. + */ + list_add_tail(&req->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); + } + + spin_unlock_irqrestore(&video->req_lock, flags); + } } static int @@ -771,7 +744,7 @@ int uvcg_video_enable(struct uvc_video *video) atomic_set(&video->queued, 0); - uvc_video_ep_queue_initial_requests(video); + kthread_queue_work(video->kworker, &video->hw_submit); queue_work(video->async_wq, &video->pump); return ret; @@ -794,6 +767,17 @@ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) if (!video->async_wq) return -EINVAL; + /* Allocate a kthread for asynchronous hw submit handler. */ + video->kworker = kthread_create_worker(0, "UVCG"); + if (IS_ERR(video->kworker)) { + uvcg_err(&video->uvc->func, "failed to create UVCG kworker\n"); + return PTR_ERR(video->kworker); + } + + kthread_init_work(&video->hw_submit, uvcg_video_hw_submit); + + sched_set_fifo(video->kworker->task); + video->uvc = uvc; video->fcc = V4L2_PIX_FMT_YUYV; video->bpp = 16;