diff -uprN -X linux-2.6.24-rc1.org/Documentation/dontdiff linux-2.6.24-rc1.org/drivers/usb/misc/adutux.c linux-2.6.24-rc1.my/drivers/usb/misc/adutux.c
--- linux-2.6.24-rc1.org/drivers/usb/misc/adutux.c	2007-10-29 15:24:15.000000000 +0200
+++ linux-2.6.24-rc1.my/drivers/usb/misc/adutux.c	2007-10-29 19:01:10.000000000 +0200
@@ -295,33 +295,36 @@ static int adu_open(struct inode *inode,
 		goto exit_no_device;
 	}
 
+	/* check that nobody else is using the device */
+	if (dev->open_count) {
+		retval = -EBUSY;
+		goto exit_no_device;
+	}
+
 	++dev->open_count;
 	dbg(2,"%s : open count %d", __FUNCTION__, dev->open_count);
 
 	/* save device in the file's private structure */
 	file->private_data = dev;
 
-	if (dev->open_count == 1) {
-		/* initialize in direction */
-		dev->read_buffer_length = 0;
+	/* initialize in direction */
+	dev->read_buffer_length = 0;
 
-		/* fixup first read by having urb waiting for it */
-		mutex_lock(&dev->mtx);		// protect udev
-		usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
-				 usb_rcvintpipe(dev->udev,
-				 		dev->interrupt_in_endpoint->bEndpointAddress),
-				 dev->interrupt_in_buffer,
-				 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
-				 adu_interrupt_in_callback, dev,
-				 dev->interrupt_in_endpoint->bInterval);
-		dev->read_urb_finished = 0;
-		retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
-		if (retval) {
-			dev->read_urb_finished = 1;
-			--dev->open_count;
-		}
-		mutex_unlock(&dev->mtx);
-	}
+	/* fixup first read by having urb waiting for it */
+	usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
+			 usb_rcvintpipe(dev->udev,
+					dev->interrupt_in_endpoint->bEndpointAddress),
+			 dev->interrupt_in_buffer,
+			 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
+			 adu_interrupt_in_callback, dev,
+			 dev->interrupt_in_endpoint->bInterval);
+	dev->read_urb_finished = 0;
+	retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
+	/* we ignore failure */
+	/* end of fixup for first read */
+
+	/* initialize out direction */
+	dev->out_urb_finished = 1;
 
 	retval = 0;
 
@@ -482,7 +485,7 @@ static ssize_t adu_read(struct file *fil
 							 adu_interrupt_in_callback,
 							 dev,
 							 dev->interrupt_in_endpoint->bInterval);
-					retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
+					retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 					if (retval) {
 						dev->read_urb_finished = 1;
 						if (retval == -ENOMEM) {