X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Fusb%2Fgadget%2Ffunction%2Fu_ether.c;h=4119dbb736027d1c0a5e7c71758455e89e5d9350;hb=398a708ed5f3ef771d96dfb9b95b5d5170d17eb7;hp=6554322af2c16a076385ba021b8ee15c8483bdc1;hpb=06a691e64b11323a735db3c3bd909d3c0712698f;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c
index 6554322af2c1..4119dbb73602 100644
--- a/drivers/usb/gadget/function/u_ether.c
+++ b/drivers/usb/gadget/function/u_ether.c
@@ -53,6 +53,8 @@
  * blocks and still have efficient handling. */
 #define GETHER_MAX_ETH_FRAME_LEN 15412
 
+static struct workqueue_struct	*uether_wq;
+
 struct eth_dev {
 	/* lock is held while accessing port_usb
 	 */
@@ -71,12 +73,14 @@ struct eth_dev {
 	unsigned		qmult;
 
 	unsigned		header_len;
+	unsigned		ul_max_pkts_per_xfer;
 	struct sk_buff		*(*wrap)(struct gether *, struct sk_buff *skb);
 	int			(*unwrap)(struct gether *,
 						struct sk_buff *skb,
 						struct sk_buff_head *list);
 
 	struct work_struct	work;
+	struct work_struct	rx_work;
 
 	unsigned long		todo;
 #define	WORK_RX_MEMORY		0
@@ -230,9 +234,13 @@ rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
 	size += out->maxpacket - 1;
 	size -= size % out->maxpacket;
 
+	if (dev->ul_max_pkts_per_xfer)
+		size *= dev->ul_max_pkts_per_xfer;
+
 	if (dev->port_usb->is_fixed)
 		size = max_t(size_t, size, dev->port_usb->fixed_out_len);
 
+	DBG(dev, "%s: size: %d\n", __func__, size);
 	skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
 	if (skb == NULL) {
 		DBG(dev, "no rx skb\n");
@@ -258,18 +266,16 @@ enomem:
 		DBG(dev, "rx submit --> %d\n", retval);
 		if (skb)
 			dev_kfree_skb_any(skb);
-		spin_lock_irqsave(&dev->req_lock, flags);
-		list_add(&req->list, &dev->rx_reqs);
-		spin_unlock_irqrestore(&dev->req_lock, flags);
 	}
 	return retval;
 }
 
 static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 {
-	struct sk_buff	*skb = req->context, *skb2;
+	struct sk_buff	*skb = req->context;
 	struct eth_dev	*dev = ep->driver_data;
 	int		status = req->status;
+	bool		queue = 0;
 
 	switch (status) {
 
@@ -293,30 +299,8 @@ static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 		} else {
 			skb_queue_tail(&dev->rx_frames, skb);
 		}
-		skb = NULL;
-
-		skb2 = skb_dequeue(&dev->rx_frames);
-		while (skb2) {
-			if (status < 0
-					|| ETH_HLEN > skb2->len
-					|| skb2->len > GETHER_MAX_ETH_FRAME_LEN) {
-				dev->net->stats.rx_errors++;
-				dev->net->stats.rx_length_errors++;
-				DBG(dev, "rx length %d\n", skb2->len);
-				dev_kfree_skb_any(skb2);
-				goto next_frame;
-			}
-			skb2->protocol = eth_type_trans(skb2, dev->net);
-			dev->net->stats.rx_packets++;
-			dev->net->stats.rx_bytes += skb2->len;
-
-			/* no buffer copies needed, unless hardware can't
-			 * use skb buffers.
-			 */
-			status = netif_rx(skb2);
-next_frame:
-			skb2 = skb_dequeue(&dev->rx_frames);
-		}
+		if (!status)
+			queue = 1;
 		break;
 
 	/* software-driven interface shutdown */
@@ -339,22 +323,20 @@ quiesce:
 		/* FALLTHROUGH */
 
 	default:
+		queue = 1;
+		dev_kfree_skb_any(skb);
 		dev->net->stats.rx_errors++;
 		DBG(dev, "rx status %d\n", status);
 		break;
 	}
 
-	if (skb)
-		dev_kfree_skb_any(skb);
-	if (!netif_running(dev->net)) {
 clean:
-		spin_lock(&dev->req_lock);
-		list_add(&req->list, &dev->rx_reqs);
-		spin_unlock(&dev->req_lock);
-		req = NULL;
-	}
-	if (req)
-		rx_submit(dev, req, GFP_ATOMIC);
+	spin_lock(&dev->req_lock);
+	list_add(&req->list, &dev->rx_reqs);
+	spin_unlock(&dev->req_lock);
+
+	if (queue)
+		queue_work(uether_wq, &dev->rx_work);
 }
 
 static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
@@ -419,16 +401,24 @@ static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
 {
 	struct usb_request	*req;
 	unsigned long		flags;
+	int			req_cnt = 0;
 
 	/* fill unused rxq slots with some skb */
 	spin_lock_irqsave(&dev->req_lock, flags);
 	while (!list_empty(&dev->rx_reqs)) {
+		/* break the nexus of continuous completion and re-submission*/
+		if (++req_cnt > qlen(dev->gadget))
+			break;
+
 		req = container_of(dev->rx_reqs.next,
 				struct usb_request, list);
 		list_del_init(&req->list);
 		spin_unlock_irqrestore(&dev->req_lock, flags);
 
 		if (rx_submit(dev, req, gfp_flags) < 0) {
+			spin_lock_irqsave(&dev->req_lock, flags);
+			list_add(&req->list, &dev->rx_reqs);
+			spin_unlock_irqrestore(&dev->req_lock, flags);
 			defer_kevent(dev, WORK_RX_MEMORY);
 			return;
 		}
@@ -438,6 +428,36 @@ static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
 	spin_unlock_irqrestore(&dev->req_lock, flags);
 }
 
+static void process_rx_w(struct work_struct *work)
+{
+	struct eth_dev	*dev = container_of(work, struct eth_dev, rx_work);
+	struct sk_buff	*skb;
+	int		status = 0;
+
+	if (!dev->port_usb)
+		return;
+
+	while ((skb = skb_dequeue(&dev->rx_frames))) {
+		if (status < 0
+				|| ETH_HLEN > skb->len
+				|| skb->len > ETH_FRAME_LEN) {
+			dev->net->stats.rx_errors++;
+			dev->net->stats.rx_length_errors++;
+			DBG(dev, "rx length %d\n", skb->len);
+			dev_kfree_skb_any(skb);
+			continue;
+		}
+		skb->protocol = eth_type_trans(skb, dev->net);
+		dev->net->stats.rx_packets++;
+		dev->net->stats.rx_bytes += skb->len;
+
+		status = netif_rx_ni(skb);
+	}
+
+	if (netif_running(dev->net))
+		rx_fill(dev, GFP_KERNEL);
+}
+
 static void eth_work(struct work_struct *work)
 {
 	struct eth_dev	*dev = container_of(work, struct eth_dev, work);
@@ -781,6 +801,7 @@ struct eth_dev *gether_setup_name(struct usb_gadget *g,
 	spin_lock_init(&dev->lock);
 	spin_lock_init(&dev->req_lock);
 	INIT_WORK(&dev->work, eth_work);
+	INIT_WORK(&dev->rx_work, process_rx_w);
 	INIT_LIST_HEAD(&dev->tx_reqs);
 	INIT_LIST_HEAD(&dev->rx_reqs);
 
@@ -1077,6 +1098,7 @@ struct net_device *gether_connect(struct gether *link)
 		dev->header_len = link->header_len;
 		dev->unwrap = link->unwrap;
 		dev->wrap = link->wrap;
+		dev->ul_max_pkts_per_xfer = link->ul_max_pkts_per_xfer;
 
 		spin_lock(&dev->lock);
 		dev->port_usb = link;
@@ -1123,6 +1145,7 @@ void gether_disconnect(struct gether *link)
 {
 	struct eth_dev		*dev = link->ioport;
 	struct usb_request	*req;
+	struct sk_buff		*skb;
 
 	WARN_ON(!dev);
 	if (!dev)
@@ -1163,6 +1186,12 @@ void gether_disconnect(struct gether *link)
 		spin_lock(&dev->req_lock);
 	}
 	spin_unlock(&dev->req_lock);
+
+	spin_lock(&dev->rx_frames.lock);
+	while ((skb = __skb_dequeue(&dev->rx_frames)))
+		dev_kfree_skb_any(skb);
+	spin_unlock(&dev->rx_frames.lock);
+
 	link->out_ep->desc = NULL;
 
 	/* finish forgetting about this USB link episode */
@@ -1176,5 +1205,23 @@ void gether_disconnect(struct gether *link)
 }
 EXPORT_SYMBOL_GPL(gether_disconnect);
 
-MODULE_LICENSE("GPL");
+static int __init gether_init(void)
+{
+	uether_wq  = create_singlethread_workqueue("uether");
+	if (!uether_wq) {
+		pr_err("%s: Unable to create workqueue: uether\n", __func__);
+		return -ENOMEM;
+	}
+	return 0;
+}
+module_init(gether_init);
+
+static void __exit gether_exit(void)
+{
+	destroy_workqueue(uether_wq);
+
+}
+module_exit(gether_exit);
 MODULE_AUTHOR("David Brownell");
+MODULE_DESCRIPTION("ethernet over USB driver");
+MODULE_LICENSE("GPL v2");