1 files changed, 19 insertions, 7 deletions

diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index e4f7828ae75d..1857d786110b 100644
--- a/drivers/usb/gadget/function/f_printer.c
+++ b/drivers/usb/gadget/function/f_printer.c
@@ -363,12 +363,11 @@ printer_open(struct inode *inode, struct file *fd)
 		ret = 0;
 		/* Change the printer status to show that it's on-line. */
 		dev->printer_status |= PRINTER_SELECTED;
+		kref_get(&dev->kref);
 	}
 
 	spin_unlock_irqrestore(&dev->lock, flags);
 
-	kref_get(&dev->kref);
-
 	return ret;
 }
 
@@ -432,7 +431,7 @@ printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 {
 	struct printer_dev		*dev = fd->private_data;
 	unsigned long			flags;
-	size_t				size;
+	size_t				size, not_copied, copied;
 	size_t				bytes_copied;
 	struct usb_request		*req;
 	/* This is a pointer to the current USB rx request. */
@@ -525,10 +524,12 @@ printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 		else
 			size = len;
 
-		size -= copy_to_user(buf, current_rx_buf, size);
-		bytes_copied += size;
-		len -= size;
-		buf += size;
+		not_copied = copy_to_user(buf, current_rx_buf, size);
+		copied = size - not_copied;
+
+		bytes_copied += copied;
+		len -= copied;
+		buf += copied;
 
 		spin_lock_irqsave(&dev->lock, flags);
 
@@ -543,6 +544,17 @@ printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 		if (dev->interface < 0)
 			goto out_disabled;
 
+		if (!copied) {
+			dev->current_rx_req = current_rx_req;
+			dev->current_rx_bytes = current_rx_bytes;
+			dev->current_rx_buf = current_rx_buf;
+			spin_unlock_irqrestore(&dev->lock, flags);
+			mutex_unlock(&dev->lock_printer_io);
+			return bytes_copied ? bytes_copied : -EFAULT;
+		}
+
+		size = copied;
+
 		/* If we not returning all the data left in this RX request
 		 * buffer then adjust the amount of data left in the buffer.
 		 * Othewise if we are done with this RX request buffer then