1 files changed, 171 insertions, 103 deletions

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index 86a99f461fd8..84525ff04745 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1094,21 +1094,54 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
 	return data[0];
 }
 
-static void uvc_video_decode_data(struct uvc_streaming *stream,
+/*
+ * uvc_video_decode_data_work: Asynchronous memcpy processing
+ *
+ * Copy URB data to video buffers in process context, releasing buffer
+ * references and requeuing the URB when done.
+ */
+static void uvc_video_copy_data_work(struct work_struct *work)
+{
+	struct uvc_urb *uvc_urb = container_of(work, struct uvc_urb, work);
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < uvc_urb->async_operations; i++) {
+		struct uvc_copy_op *op = &uvc_urb->copy_operations[i];
+
+		memcpy(op->dst, op->src, op->len);
+
+		/* Release reference taken on this buffer. */
+		uvc_queue_buffer_release(op->buf);
+	}
+
+	ret = usb_submit_urb(uvc_urb->urb, GFP_KERNEL);
+	if (ret < 0)
+		uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
+			   ret);
+}
+
+static void uvc_video_decode_data(struct uvc_urb *uvc_urb,
 		struct uvc_buffer *buf, const u8 *data, int len)
 {
-	unsigned int maxlen, nbytes;
-	void *mem;
+	unsigned int active_op = uvc_urb->async_operations;
+	struct uvc_copy_op *op = &uvc_urb->copy_operations[active_op];
+	unsigned int maxlen;
 
 	if (len <= 0)
 		return;
 
-	/* Copy the video data to the buffer. */
 	maxlen = buf->length - buf->bytesused;
-	mem = buf->mem + buf->bytesused;
-	nbytes = min((unsigned int)len, maxlen);
-	memcpy(mem, data, nbytes);
-	buf->bytesused += nbytes;
+
+	/* Take a buffer reference for async work. */
+	kref_get(&buf->ref);
+
+	op->buf = buf;
+	op->src = data;
+	op->dst = buf->mem + buf->bytesused;
+	op->len = min_t(unsigned int, len, maxlen);
+
+	buf->bytesused += op->len;
 
 	/* Complete the current frame if the buffer size was exceeded. */
 	if (len > maxlen) {
@@ -1116,6 +1149,8 @@ static void uvc_video_decode_data(struct uvc_streaming *stream,
 		buf->error = 1;
 		buf->state = UVC_BUF_STATE_READY;
 	}
+
+	uvc_urb->async_operations++;
 }
 
 static void uvc_video_decode_end(struct uvc_streaming *stream,
@@ -1291,9 +1326,11 @@ static void uvc_video_next_buffers(struct uvc_streaming *stream,
 	*video_buf = uvc_queue_next_buffer(&stream->queue, *video_buf);
 }
 
-static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
+static void uvc_video_decode_isoc(struct uvc_urb *uvc_urb,
 			struct uvc_buffer *buf, struct uvc_buffer *meta_buf)
 {
+	struct urb *urb = uvc_urb->urb;
+	struct uvc_streaming *stream = uvc_urb->stream;
 	u8 *mem;
 	int ret, i;
 
@@ -1322,7 +1359,7 @@ static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
 		uvc_video_decode_meta(stream, meta_buf, mem, ret);
 
 		/* Decode the payload data. */
-		uvc_video_decode_data(stream, buf, mem + ret,
+		uvc_video_decode_data(uvc_urb, buf, mem + ret,
 			urb->iso_frame_desc[i].actual_length - ret);
 
 		/* Process the header again. */
@@ -1334,9 +1371,11 @@ static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
 	}
 }
 
-static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
+static void uvc_video_decode_bulk(struct uvc_urb *uvc_urb,
 			struct uvc_buffer *buf, struct uvc_buffer *meta_buf)
 {
+	struct urb *urb = uvc_urb->urb;
+	struct uvc_streaming *stream = uvc_urb->stream;
 	u8 *mem;
 	int len, ret;
 
@@ -1380,9 +1419,9 @@ static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
 	 * sure buf is never dereferenced if NULL.
 	 */
 
-	/* Process video data. */
+	/* Prepare video data for processing. */
 	if (!stream->bulk.skip_payload && buf != NULL)
-		uvc_video_decode_data(stream, buf, mem, len);
+		uvc_video_decode_data(uvc_urb, buf, mem, len);
 
 	/* Detect the payload end by a URB smaller than the maximum size (or
 	 * a payload size equal to the maximum) and process the header again.
@@ -1402,9 +1441,12 @@ static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
 	}
 }
 
-static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
+static void uvc_video_encode_bulk(struct uvc_urb *uvc_urb,
 	struct uvc_buffer *buf, struct uvc_buffer *meta_buf)
 {
+	struct urb *urb = uvc_urb->urb;
+	struct uvc_streaming *stream = uvc_urb->stream;
+
 	u8 *mem = urb->transfer_buffer;
 	int len = stream->urb_size, ret;
 
@@ -1447,7 +1489,8 @@ static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
 
 static void uvc_video_complete(struct urb *urb)
 {
-	struct uvc_streaming *stream = urb->context;
+	struct uvc_urb *uvc_urb = urb->context;
+	struct uvc_streaming *stream = uvc_urb->stream;
 	struct uvc_video_queue *queue = &stream->queue;
 	struct uvc_video_queue *qmeta = &stream->meta.queue;
 	struct vb2_queue *vb2_qmeta = stream->meta.vdev.queue;
@@ -1464,7 +1507,7 @@ static void uvc_video_complete(struct urb *urb)
 		uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
 			"completion handler.\n", urb->status);
 		/* fall through */
-	case -ENOENT:		/* usb_kill_urb() called. */
+	case -ENOENT:		/* usb_poison_urb() called. */
 		if (stream->frozen)
 			return;
 		/* fall through */
@@ -1476,11 +1519,7 @@ static void uvc_video_complete(struct urb *urb)
 		return;
 	}
 
-	spin_lock_irqsave(&queue->irqlock, flags);
-	if (!list_empty(&queue->irqqueue))
-		buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
-				       queue);
-	spin_unlock_irqrestore(&queue->irqlock, flags);
+	buf = uvc_queue_get_current_buffer(queue);
 
 	if (vb2_qmeta) {
 		spin_lock_irqsave(&qmeta->irqlock, flags);
@@ -1490,12 +1529,26 @@ static void uvc_video_complete(struct urb *urb)
 		spin_unlock_irqrestore(&qmeta->irqlock, flags);
 	}
 
-	stream->decode(urb, stream, buf, buf_meta);
+	/* Re-initialise the URB async work. */
+	uvc_urb->async_operations = 0;
 
-	if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
-		uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
-			ret);
+	/*
+	 * Process the URB headers, and optionally queue expensive memcpy tasks
+	 * to be deferred to a work queue.
+	 */
+	stream->decode(uvc_urb, buf, buf_meta);
+
+	/* If no async work is needed, resubmit the URB immediately. */
+	if (!uvc_urb->async_operations) {
+		ret = usb_submit_urb(uvc_urb->urb, GFP_ATOMIC);
+		if (ret < 0)
+			uvc_printk(KERN_ERR,
+				   "Failed to resubmit video URB (%d).\n",
+				   ret);
+		return;
 	}
+
+	queue_work(stream->async_wq, &uvc_urb->work);
 }
 
 /*
@@ -1503,18 +1556,19 @@ static void uvc_video_complete(struct urb *urb)
  */
 static void uvc_free_urb_buffers(struct uvc_streaming *stream)
 {
-	unsigned int i;
+	struct uvc_urb *uvc_urb;
+
+	for_each_uvc_urb(uvc_urb, stream) {
+		if (!uvc_urb->buffer)
+			continue;
 
-	for (i = 0; i < UVC_URBS; ++i) {
-		if (stream->urb_buffer[i]) {
 #ifndef CONFIG_DMA_NONCOHERENT
-			usb_free_coherent(stream->dev->udev, stream->urb_size,
-				stream->urb_buffer[i], stream->urb_dma[i]);
+		usb_free_coherent(stream->dev->udev, stream->urb_size,
+				  uvc_urb->buffer, uvc_urb->dma);
 #else
-			kfree(stream->urb_buffer[i]);
+		kfree(uvc_urb->buffer);
 #endif
-			stream->urb_buffer[i] = NULL;
-		}
+		uvc_urb->buffer = NULL;
 	}
 
 	stream->urb_size = 0;
@@ -1551,19 +1605,23 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
 	/* Retry allocations until one succeed. */
 	for (; npackets > 1; npackets /= 2) {
 		for (i = 0; i < UVC_URBS; ++i) {
+			struct uvc_urb *uvc_urb = &stream->uvc_urb[i];
+
 			stream->urb_size = psize * npackets;
 #ifndef CONFIG_DMA_NONCOHERENT
-			stream->urb_buffer[i] = usb_alloc_coherent(
+			uvc_urb->buffer = usb_alloc_coherent(
 				stream->dev->udev, stream->urb_size,
-				gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
+				gfp_flags | __GFP_NOWARN, &uvc_urb->dma);
 #else
-			stream->urb_buffer[i] =
+			uvc_urb->buffer =
 			    kmalloc(stream->urb_size, gfp_flags | __GFP_NOWARN);
 #endif
-			if (!stream->urb_buffer[i]) {
+			if (!uvc_urb->buffer) {
 				uvc_free_urb_buffers(stream);
 				break;
 			}
+
+			uvc_urb->stream = stream;
 		}
 
 		if (i == UVC_URBS) {
@@ -1582,21 +1640,26 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
 /*
  * Uninitialize isochronous/bulk URBs and free transfer buffers.
  */
-static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
+static void uvc_video_stop_transfer(struct uvc_streaming *stream,
+				    int free_buffers)
 {
-	struct urb *urb;
-	unsigned int i;
+	struct uvc_urb *uvc_urb;
 
 	uvc_video_stats_stop(stream);
 
-	for (i = 0; i < UVC_URBS; ++i) {
-		urb = stream->urb[i];
-		if (urb == NULL)
-			continue;
+	/*
+	 * We must poison the URBs rather than kill them to ensure that even
+	 * after the completion handler returns, any asynchronous workqueues
+	 * will be prevented from resubmitting the URBs.
+	 */
+	for_each_uvc_urb(uvc_urb, stream)
+		usb_poison_urb(uvc_urb->urb);
 
-		usb_kill_urb(urb);
-		usb_free_urb(urb);
-		stream->urb[i] = NULL;
+	flush_workqueue(stream->async_wq);
+
+	for_each_uvc_urb(uvc_urb, stream) {
+		usb_free_urb(uvc_urb->urb);
+		uvc_urb->urb = NULL;
 	}
 
 	if (free_buffers)
@@ -1637,7 +1700,8 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
 	struct usb_host_endpoint *ep, gfp_t gfp_flags)
 {
 	struct urb *urb;
-	unsigned int npackets, i, j;
+	struct uvc_urb *uvc_urb;
+	unsigned int npackets, i;
 	u16 psize;
 	u32 size;
 
@@ -1650,35 +1714,35 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
 
 	size = npackets * psize;
 
-	for (i = 0; i < UVC_URBS; ++i) {
+	for_each_uvc_urb(uvc_urb, stream) {
 		urb = usb_alloc_urb(npackets, gfp_flags);
 		if (urb == NULL) {
-			uvc_uninit_video(stream, 1);
+			uvc_video_stop_transfer(stream, 1);
 			return -ENOMEM;
 		}
 
 		urb->dev = stream->dev->udev;
-		urb->context = stream;
+		urb->context = uvc_urb;
 		urb->pipe = usb_rcvisocpipe(stream->dev->udev,
 				ep->desc.bEndpointAddress);
 #ifndef CONFIG_DMA_NONCOHERENT
 		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
-		urb->transfer_dma = stream->urb_dma[i];
+		urb->transfer_dma = uvc_urb->dma;
 #else
 		urb->transfer_flags = URB_ISO_ASAP;
 #endif
 		urb->interval = ep->desc.bInterval;
-		urb->transfer_buffer = stream->urb_buffer[i];
+		urb->transfer_buffer = uvc_urb->buffer;
 		urb->complete = uvc_video_complete;
 		urb->number_of_packets = npackets;
 		urb->transfer_buffer_length = size;
 
-		for (j = 0; j < npackets; ++j) {
-			urb->iso_frame_desc[j].offset = j * psize;
-			urb->iso_frame_desc[j].length = psize;
+		for (i = 0; i < npackets; ++i) {
+			urb->iso_frame_desc[i].offset = i * psize;
+			urb->iso_frame_desc[i].length = psize;
 		}
 
-		stream->urb[i] = urb;
+		uvc_urb->urb = urb;
 	}
 
 	return 0;
@@ -1692,7 +1756,8 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
 	struct usb_host_endpoint *ep, gfp_t gfp_flags)
 {
 	struct urb *urb;
-	unsigned int npackets, pipe, i;
+	struct uvc_urb *uvc_urb;
+	unsigned int npackets, pipe;
 	u16 psize;
 	u32 size;
 
@@ -1716,22 +1781,21 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
 	if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
 		size = 0;
 
-	for (i = 0; i < UVC_URBS; ++i) {
+	for_each_uvc_urb(uvc_urb, stream) {
 		urb = usb_alloc_urb(0, gfp_flags);
 		if (urb == NULL) {
-			uvc_uninit_video(stream, 1);
+			uvc_video_stop_transfer(stream, 1);
 			return -ENOMEM;
 		}
 
-		usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
-			stream->urb_buffer[i], size, uvc_video_complete,
-			stream);
+		usb_fill_bulk_urb(urb, stream->dev->udev, pipe,	uvc_urb->buffer,
+				  size, uvc_video_complete, uvc_urb);
 #ifndef CONFIG_DMA_NONCOHERENT
 		urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
-		urb->transfer_dma = stream->urb_dma[i];
+		urb->transfer_dma = uvc_urb->dma;
 #endif
 
-		stream->urb[i] = urb;
+		uvc_urb->urb = urb;
 	}
 
 	return 0;
@@ -1740,10 +1804,12 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
 /*
  * Initialize isochronous/bulk URBs and allocate transfer buffers.
  */
-static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
+static int uvc_video_start_transfer(struct uvc_streaming *stream,
+				    gfp_t gfp_flags)
 {
 	struct usb_interface *intf = stream->intf;
 	struct usb_host_endpoint *ep;
+	struct uvc_urb *uvc_urb;
 	unsigned int i;
 	int ret;
 
@@ -1821,12 +1887,12 @@ static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
 		return ret;
 
 	/* Submit the URBs. */
-	for (i = 0; i < UVC_URBS; ++i) {
-		ret = usb_submit_urb(stream->urb[i], gfp_flags);
+	for_each_uvc_urb(uvc_urb, stream) {
+		ret = usb_submit_urb(uvc_urb->urb, gfp_flags);
 		if (ret < 0) {
-			uvc_printk(KERN_ERR, "Failed to submit URB %u "
-					"(%d).\n", i, ret);
-			uvc_uninit_video(stream, 1);
+			uvc_printk(KERN_ERR, "Failed to submit URB %u (%d).\n",
+				   uvc_urb_index(uvc_urb), ret);
+			uvc_video_stop_transfer(stream, 1);
 			return ret;
 		}
 	}
@@ -1857,7 +1923,7 @@ int uvc_video_suspend(struct uvc_streaming *stream)
 		return 0;
 
 	stream->frozen = 1;
-	uvc_uninit_video(stream, 0);
+	uvc_video_stop_transfer(stream, 0);
 	usb_set_interface(stream->dev->udev, stream->intfnum, 0);
 	return 0;
 }
@@ -1893,7 +1959,7 @@ int uvc_video_resume(struct uvc_streaming *stream, int reset)
 	if (ret < 0)
 		return ret;
 
-	return uvc_init_video(stream, GFP_NOIO);
+	return uvc_video_start_transfer(stream, GFP_NOIO);
 }
 
 /* ------------------------------------------------------------------------
@@ -1915,6 +1981,7 @@ int uvc_video_init(struct uvc_streaming *stream)
 	struct uvc_streaming_control *probe = &stream->ctrl;
 	struct uvc_format *format = NULL;
 	struct uvc_frame *frame = NULL;
+	struct uvc_urb *uvc_urb;
 	unsigned int i;
 	int ret;
 
@@ -2000,41 +2067,17 @@ int uvc_video_init(struct uvc_streaming *stream)
 		}
 	}
 
+	/* Prepare asynchronous work items. */
+	for_each_uvc_urb(uvc_urb, stream)
+		INIT_WORK(&uvc_urb->work, uvc_video_copy_data_work);
+
 	return 0;
 }
 
-/*
- * Enable or disable the video stream.
- */
-int uvc_video_enable(struct uvc_streaming *stream, int enable)
+int uvc_video_start_streaming(struct uvc_streaming *stream)
 {
 	int ret;
 
-	if (!enable) {
-		uvc_uninit_video(stream, 1);
-		if (stream->intf->num_altsetting > 1) {
-			usb_set_interface(stream->dev->udev,
-					  stream->intfnum, 0);
-		} else {
-			/* UVC doesn't specify how to inform a bulk-based device
-			 * when the video stream is stopped. Windows sends a
-			 * CLEAR_FEATURE(HALT) request to the video streaming
-			 * bulk endpoint, mimic the same behaviour.
-			 */
-			unsigned int epnum = stream->header.bEndpointAddress
-					   & USB_ENDPOINT_NUMBER_MASK;
-			unsigned int dir = stream->header.bEndpointAddress
-					 & USB_ENDPOINT_DIR_MASK;
-			unsigned int pipe;
-
-			pipe = usb_sndbulkpipe(stream->dev->udev, epnum) | dir;
-			usb_clear_halt(stream->dev->udev, pipe);
-		}
-
-		uvc_video_clock_cleanup(stream);
-		return 0;
-	}
-
 	ret = uvc_video_clock_init(stream);
 	if (ret < 0)
 		return ret;
@@ -2044,7 +2087,7 @@ int uvc_video_enable(struct uvc_streaming *stream, int enable)
 	if (ret < 0)
 		goto error_commit;
 
-	ret = uvc_init_video(stream, GFP_KERNEL);
+	ret = uvc_video_start_transfer(stream, GFP_KERNEL);
 	if (ret < 0)
 		goto error_video;
 
@@ -2057,3 +2100,28 @@ error_commit:
 
 	return ret;
 }
+
+void uvc_video_stop_streaming(struct uvc_streaming *stream)
+{
+	uvc_video_stop_transfer(stream, 1);
+
+	if (stream->intf->num_altsetting > 1) {
+		usb_set_interface(stream->dev->udev, stream->intfnum, 0);
+	} else {
+		/* UVC doesn't specify how to inform a bulk-based device
+		 * when the video stream is stopped. Windows sends a
+		 * CLEAR_FEATURE(HALT) request to the video streaming
+		 * bulk endpoint, mimic the same behaviour.
+		 */
+		unsigned int epnum = stream->header.bEndpointAddress
+				   & USB_ENDPOINT_NUMBER_MASK;
+		unsigned int dir = stream->header.bEndpointAddress
+				 & USB_ENDPOINT_DIR_MASK;
+		unsigned int pipe;
+
+		pipe = usb_sndbulkpipe(stream->dev->udev, epnum) | dir;
+		usb_clear_halt(stream->dev->udev, pipe);
+	}
+
+	uvc_video_clock_cleanup(stream);
+}