1 files changed, 54 insertions, 32 deletions

diff --git a/drivers/usb/gadget/printer.c b/drivers/usb/gadget/printer.c
index 2c32bd08ee7..ecc1410073f 100644
--- a/drivers/usb/gadget/printer.c
+++ b/drivers/usb/gadget/printer.c
@@ -390,9 +390,12 @@ static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 
 	/* normal completion */
 	case 0:
-		list_add_tail(&req->list, &dev->rx_buffers);
-		wake_up_interruptible(&dev->rx_wait);
-		DBG(dev, "G_Printer : rx length %d\n", req->actual);
+		if (req->actual > 0) {
+			list_add_tail(&req->list, &dev->rx_buffers);
+			DBG(dev, "G_Printer : rx length %d\n", req->actual);
+		} else {
+			list_add(&req->list, &dev->rx_reqs);
+		}
 		break;
 
 	/* software-driven interface shutdown */
@@ -417,6 +420,8 @@ static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 		list_add(&req->list, &dev->rx_reqs);
 		break;
 	}
+
+	wake_up_interruptible(&dev->rx_wait);
 	spin_unlock_irqrestore(&dev->lock, flags);
 }
 
@@ -494,6 +499,39 @@ printer_close(struct inode *inode, struct file *fd)
 	return 0;
 }
 
+/* This function must be called with interrupts turned off. */
+static void
+setup_rx_reqs(struct printer_dev *dev)
+{
+	struct usb_request              *req;
+
+	while (likely(!list_empty(&dev->rx_reqs))) {
+		int error;
+
+		req = container_of(dev->rx_reqs.next,
+				struct usb_request, list);
+		list_del_init(&req->list);
+
+		/* The USB Host sends us whatever amount of data it wants to
+		 * so we always set the length field to the full USB_BUFSIZE.
+		 * If the amount of data is more than the read() caller asked
+		 * for it will be stored in the request buffer until it is
+		 * asked for by read().
+		 */
+		req->length = USB_BUFSIZE;
+		req->complete = rx_complete;
+
+		error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
+		if (error) {
+			DBG(dev, "rx submit --> %d\n", error);
+			list_add(&req->list, &dev->rx_reqs);
+			break;
+		} else {
+			list_add(&req->list, &dev->rx_reqs_active);
+		}
+	}
+}
+
 static ssize_t
 printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 {
@@ -522,31 +560,7 @@ printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 	 */
 	dev->reset_printer = 0;
 
-	while (likely(!list_empty(&dev->rx_reqs))) {
-		int error;
-
-		req = container_of(dev->rx_reqs.next,
-				struct usb_request, list);
-		list_del_init(&req->list);
-
-		/* The USB Host sends us whatever amount of data it wants to
-		 * so we always set the length field to the full USB_BUFSIZE.
-		 * If the amount of data is more than the read() caller asked
-		 * for it will be stored in the request buffer until it is
-		 * asked for by read().
-		 */
-		req->length = USB_BUFSIZE;
-		req->complete = rx_complete;
-
-		error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
-		if (error) {
-			DBG(dev, "rx submit --> %d\n", error);
-			list_add(&req->list, &dev->rx_reqs);
-			break;
-		} else {
-			list_add(&req->list, &dev->rx_reqs_active);
-		}
-	}
+	setup_rx_reqs(dev);
 
 	bytes_copied = 0;
 	current_rx_req = dev->current_rx_req;
@@ -615,9 +629,9 @@ printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 
 		spin_lock_irqsave(&dev->lock, flags);
 
-		/* We've disconnected or reset free the req and buffer */
+		/* We've disconnected or reset so return. */
 		if (dev->reset_printer) {
-			printer_req_free(dev->out_ep, current_rx_req);
+			list_add(&current_rx_req->list, &dev->rx_reqs);
 			spin_unlock_irqrestore(&dev->lock, flags);
 			spin_unlock(&dev->lock_printer_io);
 			return -EAGAIN;
@@ -735,7 +749,7 @@ printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 
 		/* We've disconnected or reset so free the req and buffer */
 		if (dev->reset_printer) {
-			printer_req_free(dev->in_ep, req);
+			list_add(&req->list, &dev->tx_reqs);
 			spin_unlock_irqrestore(&dev->lock, flags);
 			spin_unlock(&dev->lock_printer_io);
 			return -EAGAIN;
@@ -791,6 +805,12 @@ printer_poll(struct file *fd, poll_table *wait)
 	unsigned long		flags;
 	int			status = 0;
 
+	spin_lock(&dev->lock_printer_io);
+	spin_lock_irqsave(&dev->lock, flags);
+	setup_rx_reqs(dev);
+	spin_unlock_irqrestore(&dev->lock, flags);
+	spin_unlock(&dev->lock_printer_io);
+
 	poll_wait(fd, &dev->rx_wait, wait);
 	poll_wait(fd, &dev->tx_wait, wait);
 
@@ -798,7 +818,8 @@ printer_poll(struct file *fd, poll_table *wait)
 	if (likely(!list_empty(&dev->tx_reqs)))
 		status |= POLLOUT | POLLWRNORM;
 
-	if (likely(!list_empty(&dev->rx_buffers)))
+	if (likely(dev->current_rx_bytes) ||
+			likely(!list_empty(&dev->rx_buffers)))
 		status |= POLLIN | POLLRDNORM;
 
 	spin_unlock_irqrestore(&dev->lock, flags);
@@ -1084,6 +1105,7 @@ static void printer_soft_reset(struct printer_dev *dev)
 	if (usb_ep_enable(dev->out_ep, dev->out))
 		DBG(dev, "Failed to enable USB out_ep\n");
 
+	wake_up_interruptible(&dev->rx_wait);
 	wake_up_interruptible(&dev->tx_wait);
 	wake_up_interruptible(&dev->tx_flush_wait);
 }