1 files changed, 161 insertions, 107 deletions

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index 57a851151225..79e223713d8b 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -19,6 +19,7 @@
 #include "uvc.h"
 #include "uvc_queue.h"
 #include "uvc_video.h"
+#include "uvc_trace.h"
 
 /* --------------------------------------------------------------------------
  * Video codecs
@@ -78,7 +79,7 @@ uvc_video_encode_data(struct uvc_video *video, struct uvc_buffer *buf,
 
 	/* Copy video data to the USB buffer. */
 	mem = buf->mem + queue->buf_used;
-	nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used);
+	nbytes = min_t(unsigned int, len, buf->bytesused - queue->buf_used);
 
 	memcpy(data, mem, nbytes);
 	queue->buf_used += nbytes;
@@ -104,7 +105,7 @@ uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video,
 	}
 
 	/* Process video data. */
-	len = min((int)(video->max_payload_size - video->payload_size), len);
+	len = min_t(int, video->max_payload_size - video->payload_size, len);
 	ret = uvc_video_encode_data(video, buf, mem, len);
 
 	video->payload_size += ret;
@@ -136,7 +137,7 @@ uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
 	unsigned int pending = buf->bytesused - video->queue.buf_used;
 	struct uvc_request *ureq = req->context;
 	struct scatterlist *sg, *iter;
-	unsigned int len = video->req_size;
+	unsigned int len = buf->req_payload_size;
 	unsigned int sg_left, part = 0;
 	unsigned int i;
 	int header_len;
@@ -146,15 +147,15 @@ uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
 
 	/* Init the header. */
 	header_len = uvc_video_encode_header(video, buf, ureq->header,
-				      video->req_size);
+					     buf->req_payload_size);
 	sg_set_buf(sg, ureq->header, header_len);
 	len -= header_len;
 
 	if (pending <= len)
 		len = pending;
 
-	req->length = (len == pending) ?
-		len + header_len : video->req_size;
+	req->length = (len == pending) ? len + header_len :
+		buf->req_payload_size;
 
 	/* Init the pending sgs with payload */
 	sg = sg_next(sg);
@@ -202,7 +203,7 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
 {
 	void *mem = req->buf;
 	struct uvc_request *ureq = req->context;
-	int len = video->req_size;
+	int len = buf->req_payload_size;
 	int ret;
 
 	/* Add the header. */
@@ -214,7 +215,7 @@ uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
 	ret = uvc_video_encode_data(video, buf, mem, len);
 	len -= ret;
 
-	req->length = video->req_size - len;
+	req->length = buf->req_payload_size - len;
 
 	if (buf->bytesused == video->queue.buf_used ||
 			video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) {
@@ -269,6 +270,10 @@ static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
 		}
 	}
 
+	atomic_inc(&video->queued);
+
+	trace_uvcg_video_queue(req, atomic_read(&video->queued));
+
 	return ret;
 }
 
@@ -304,7 +309,7 @@ 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 {
@@ -322,50 +327,6 @@ 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)
 {
@@ -373,12 +334,10 @@ 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);
 	if (!video->is_enabled) {
 		/*
 		 * When is_enabled is false, uvcg_video_disable() ensures
@@ -438,51 +397,87 @@ 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(video->async_wq, &video->pump);
+
+	trace_uvcg_video_complete(req, atomic_read(&video->queued));
+
+	spin_unlock_irqrestore(&video->req_lock, flags);
+
+	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);
 		/*
-		 * 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.
+		 * 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(video->async_wq, &video->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.
-	 */
-	ret = uvcg_video_usb_req_queue(video, to_queue, !is_bulk);
-	if (ret < 0) {
+		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);
+
 		/*
-		 * Endpoint error, but the stream is still enabled.
-		 * Put request back in req_free for it to be cleaned
-		 * up later.
+		 * 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.
 		 */
-		list_add_tail(&to_queue->list, &video->req_free);
-	}
+		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
@@ -496,23 +491,71 @@ uvc_video_free_requests(struct uvc_video *video)
 	INIT_LIST_HEAD(&video->ureqs);
 	INIT_LIST_HEAD(&video->req_free);
 	INIT_LIST_HEAD(&video->req_ready);
-	video->req_size = 0;
 	return 0;
 }
 
+static void
+uvc_video_prep_requests(struct uvc_video *video)
+{
+	struct uvc_device *uvc = container_of(video, struct uvc_device, video);
+	struct usb_composite_dev *cdev = uvc->func.config->cdev;
+	unsigned int interval_duration = video->ep->desc->bInterval * 1250;
+	unsigned int max_req_size, req_size, header_size;
+	unsigned int nreq;
+
+	max_req_size = video->ep->maxpacket
+		 * max_t(unsigned int, video->ep->maxburst, 1)
+		 * (video->ep->mult);
+
+	if (!usb_endpoint_xfer_isoc(video->ep->desc)) {
+		video->req_size = max_req_size;
+		video->reqs_per_frame = video->uvc_num_requests =
+			DIV_ROUND_UP(video->imagesize, max_req_size);
+
+		return;
+	}
+
+	if (cdev->gadget->speed < USB_SPEED_HIGH)
+		interval_duration = video->ep->desc->bInterval * 10000;
+
+	nreq = DIV_ROUND_UP(video->interval, interval_duration);
+
+	header_size = nreq * UVCG_REQUEST_HEADER_LEN;
+
+	req_size = DIV_ROUND_UP(video->imagesize + header_size, nreq);
+
+	if (req_size > max_req_size) {
+		/* The prepared interval length and expected buffer size
+		 * is not possible to stream with the currently configured
+		 * isoc bandwidth. Fallback to the maximum.
+		 */
+		req_size = max_req_size;
+	}
+	video->req_size = req_size;
+
+	/* We need to compensate the amount of requests to be
+	 * allocated with the maximum amount of zero length requests.
+	 * Since it is possible that hw_submit will initially
+	 * enqueue some zero length requests and we then will not be
+	 * able to fully encode one frame.
+	 */
+	video->uvc_num_requests = nreq + UVCG_REQ_MAX_ZERO_COUNT;
+	video->reqs_per_frame = nreq;
+}
+
 static int
 uvc_video_alloc_requests(struct uvc_video *video)
 {
 	struct uvc_request *ureq;
-	unsigned int req_size;
 	unsigned int i;
 	int ret = -ENOMEM;
 
-	BUG_ON(video->req_size);
-
-	req_size = video->ep->maxpacket
-		 * max_t(unsigned int, video->ep->maxburst, 1)
-		 * (video->ep->mult);
+	/*
+	 * calculate in uvc_video_prep_requests
+	 * - video->uvc_num_requests
+	 * - video->req_size
+	 */
+	uvc_video_prep_requests(video);
 
 	for (i = 0; i < video->uvc_num_requests; i++) {
 		ureq = kzalloc(sizeof(struct uvc_request), GFP_KERNEL);
@@ -523,7 +566,7 @@ uvc_video_alloc_requests(struct uvc_video *video)
 
 		list_add_tail(&ureq->list, &video->ureqs);
 
-		ureq->req_buffer = kmalloc(req_size, GFP_KERNEL);
+		ureq->req_buffer = kmalloc(video->req_size, GFP_KERNEL);
 		if (ureq->req_buffer == NULL)
 			goto error;
 
@@ -541,12 +584,10 @@ uvc_video_alloc_requests(struct uvc_video *video)
 		list_add_tail(&ureq->req->list, &video->req_free);
 		/* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */
 		sg_alloc_table(&ureq->sgt,
-			       DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN,
+			       DIV_ROUND_UP(video->req_size - UVCG_REQUEST_HEADER_LEN,
 					    PAGE_SIZE) + 2, GFP_KERNEL);
 	}
 
-	video->req_size = req_size;
-
 	return 0;
 
 error:
@@ -699,7 +740,6 @@ uvcg_video_disable(struct uvc_video *video)
 	INIT_LIST_HEAD(&video->ureqs);
 	INIT_LIST_HEAD(&video->req_free);
 	INIT_LIST_HEAD(&video->req_ready);
-	video->req_size = 0;
 	spin_unlock_irqrestore(&video->req_lock, flags);
 
 	/*
@@ -752,7 +792,9 @@ int uvcg_video_enable(struct uvc_video *video)
 
 	video->req_int_count = 0;
 
-	uvc_video_ep_queue_initial_requests(video);
+	atomic_set(&video->queued, 0);
+
+	kthread_queue_work(video->kworker, &video->hw_submit);
 	queue_work(video->async_wq, &video->pump);
 
 	return ret;
@@ -775,12 +817,24 @@ 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;
 	video->width = 320;
 	video->height = 240;
 	video->imagesize = 320 * 240 * 2;
+	video->interval = 666666;
 
 	/* Initialize the video buffers queue. */
 	uvcg_queue_init(&video->queue, uvc->v4l2_dev.dev->parent,