1 files changed, 244 insertions, 307 deletions

diff --git a/drivers/usb/misc/adutux.c b/drivers/usb/misc/adutux.c
index e9fdbc8997b..493c7f268b6 100644
--- a/drivers/usb/misc/adutux.c
+++ b/drivers/usb/misc/adutux.c
@@ -18,52 +18,34 @@
  *
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/kernel.h>
 #include <linux/errno.h>
-#include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/usb.h>
 #include <linux/mutex.h>
-#include <asm/uaccess.h>
-
-#ifdef CONFIG_USB_DEBUG
-static int debug = 5;
-#else
-static int debug = 1;
-#endif
-
-/* Use our own dbg macro */
-#undef dbg
-#define dbg(lvl, format, arg...) 					\
-do { 									\
-	if (debug >= lvl)						\
-		printk(KERN_DEBUG __FILE__ " : " format " \n", ## arg);	\
-} while (0)
-
+#include <linux/uaccess.h>
 
 /* Version Information */
 #define DRIVER_VERSION "v0.0.13"
 #define DRIVER_AUTHOR "John Homppi"
 #define DRIVER_DESC "adutux (see www.ontrak.net)"
 
-/* Module parameters */
-module_param(debug, int, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(debug, "Debug enabled or not");
-
 /* Define these values to match your device */
 #define ADU_VENDOR_ID 0x0a07
 #define ADU_PRODUCT_ID 0x0064
 
 /* table of devices that work with this driver */
-static struct usb_device_id device_table [] = {
+static const struct usb_device_id device_table[] = {
 	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) },		/* ADU100 */
-	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) }, 	/* ADU120 */
-	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) }, 	/* ADU130 */
+	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) },	/* ADU120 */
+	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) },	/* ADU130 */
 	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) },	/* ADU200 */
 	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) },	/* ADU208 */
 	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) },	/* ADU218 */
-	{ }/* Terminating entry */
+	{ } /* Terminating entry */
 };
 
 MODULE_DEVICE_TABLE(usb, device_table);
@@ -79,19 +61,29 @@ MODULE_DEVICE_TABLE(usb, device_table);
 
 #define COMMAND_TIMEOUT	(2*HZ)	/* 60 second timeout for a command */
 
+/*
+ * The locking scheme is a vanilla 3-lock:
+ *   adu_device.buflock: A spinlock, covers what IRQs touch.
+ *   adutux_mutex:       A Static lock to cover open_count. It would also cover
+ *                       any globals, but we don't have them in 2.6.
+ *   adu_device.mtx:     A mutex to hold across sleepers like copy_from_user.
+ *                       It covers all of adu_device, except the open_count
+ *                       and what .buflock covers.
+ */
+
 /* Structure to hold all of our device specific stuff */
 struct adu_device {
-	struct mutex		mtx; /* locks this structure */
-	struct usb_device*	udev; /* save off the usb device pointer */
-	struct usb_interface*	interface;
-	unsigned char		minor; /* the starting minor number for this device */
+	struct mutex		mtx;
+	struct usb_device *udev; /* save off the usb device pointer */
+	struct usb_interface *interface;
+	unsigned int		minor; /* the starting minor number for this device */
 	char			serial_number[8];
 
 	int			open_count; /* number of times this port has been opened */
 
-	char*			read_buffer_primary;
+	char		*read_buffer_primary;
 	int			read_buffer_length;
-	char*			read_buffer_secondary;
+	char		*read_buffer_secondary;
 	int			secondary_head;
 	int			secondary_tail;
 	spinlock_t		buflock;
@@ -99,31 +91,26 @@ struct adu_device {
 	wait_queue_head_t	read_wait;
 	wait_queue_head_t	write_wait;
 
-	char*			interrupt_in_buffer;
-	struct usb_endpoint_descriptor* interrupt_in_endpoint;
-	struct urb*		interrupt_in_urb;
+	char		*interrupt_in_buffer;
+	struct usb_endpoint_descriptor *interrupt_in_endpoint;
+	struct urb	*interrupt_in_urb;
 	int			read_urb_finished;
 
-	char*			interrupt_out_buffer;
-	struct usb_endpoint_descriptor* interrupt_out_endpoint;
-	struct urb*		interrupt_out_urb;
+	char		*interrupt_out_buffer;
+	struct usb_endpoint_descriptor *interrupt_out_endpoint;
+	struct urb	*interrupt_out_urb;
+	int			out_urb_finished;
 };
 
+static DEFINE_MUTEX(adutux_mutex);
+
 static struct usb_driver adu_driver;
 
-static void adu_debug_data(int level, const char *function, int size,
-			   const unsigned char *data)
+static inline void adu_debug_data(struct device *dev, const char *function,
+				  int size, const unsigned char *data)
 {
-	int i;
-
-	if (debug < level)
-		return;
-
-	printk(KERN_DEBUG __FILE__": %s - length = %d, data = ",
-	       function, size);
-	for (i = 0; i < size; ++i)
-		printk("%.2x ", data[i]);
-	printk("\n");
+	dev_dbg(dev, "%s - length = %d, data = %*ph\n",
+		function, size, size, data);
 }
 
 /**
@@ -132,38 +119,31 @@ static void adu_debug_data(int level, const char *function, int size,
  */
 static void adu_abort_transfers(struct adu_device *dev)
 {
-	dbg(2," %s : enter", __FUNCTION__);
-
-	if (dev == NULL) {
-		dbg(1," %s : dev is null", __FUNCTION__);
-		goto exit;
-	}
-
-	if (dev->udev == NULL) {
-		dbg(1," %s : udev is null", __FUNCTION__);
-		goto exit;
-	}
+	unsigned long flags;
 
-	dbg(2," %s : udev state %d", __FUNCTION__, dev->udev->state);
-	if (dev->udev->state == USB_STATE_NOTATTACHED) {
-		dbg(1," %s : udev is not attached", __FUNCTION__);
-		goto exit;
-	}
+	if (dev->udev == NULL)
+		return;
 
 	/* shutdown transfer */
-	usb_unlink_urb(dev->interrupt_in_urb);
-	usb_unlink_urb(dev->interrupt_out_urb);
 
-exit:
-	dbg(2," %s : leave", __FUNCTION__);
+	/* XXX Anchor these instead */
+	spin_lock_irqsave(&dev->buflock, flags);
+	if (!dev->read_urb_finished) {
+		spin_unlock_irqrestore(&dev->buflock, flags);
+		usb_kill_urb(dev->interrupt_in_urb);
+	} else
+		spin_unlock_irqrestore(&dev->buflock, flags);
+
+	spin_lock_irqsave(&dev->buflock, flags);
+	if (!dev->out_urb_finished) {
+		spin_unlock_irqrestore(&dev->buflock, flags);
+		usb_kill_urb(dev->interrupt_out_urb);
+	} else
+		spin_unlock_irqrestore(&dev->buflock, flags);
 }
 
 static void adu_delete(struct adu_device *dev)
 {
-	dbg(2, "%s enter", __FUNCTION__);
-
-	adu_abort_transfers(dev);
-
 	/* free data structures */
 	usb_free_urb(dev->interrupt_in_urb);
 	usb_free_urb(dev->interrupt_out_urb);
@@ -172,8 +152,6 @@ static void adu_delete(struct adu_device *dev)
 	kfree(dev->interrupt_in_buffer);
 	kfree(dev->interrupt_out_buffer);
 	kfree(dev);
-
-	dbg(2, "%s : leave", __FUNCTION__);
 }
 
 static void adu_interrupt_in_callback(struct urb *urb)
@@ -181,33 +159,35 @@ static void adu_interrupt_in_callback(struct urb *urb)
 	struct adu_device *dev = urb->context;
 	int status = urb->status;
 
-	dbg(4," %s : enter, status %d", __FUNCTION__, status);
-	adu_debug_data(5, __FUNCTION__, urb->actual_length,
-		       urb->transfer_buffer);
+	adu_debug_data(&dev->udev->dev, __func__,
+		       urb->actual_length, urb->transfer_buffer);
 
 	spin_lock(&dev->buflock);
 
 	if (status != 0) {
-		if ((status != -ENOENT) && (status != -ECONNRESET)) {
-			dbg(1," %s : nonzero status received: %d",
-			    __FUNCTION__, status);
+		if ((status != -ENOENT) && (status != -ECONNRESET) &&
+			(status != -ESHUTDOWN)) {
+			dev_dbg(&dev->udev->dev,
+				"%s : nonzero status received: %d\n",
+				__func__, status);
 		}
 		goto exit;
 	}
 
 	if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
 		if (dev->read_buffer_length <
-		    (4 * le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize)) -
+		    (4 * usb_endpoint_maxp(dev->interrupt_in_endpoint)) -
 		     (urb->actual_length)) {
 			memcpy (dev->read_buffer_primary +
 				dev->read_buffer_length,
 				dev->interrupt_in_buffer, urb->actual_length);
 
 			dev->read_buffer_length += urb->actual_length;
-			dbg(2," %s reading  %d ", __FUNCTION__,
-			    urb->actual_length);
+			dev_dbg(&dev->udev->dev,"%s reading  %d\n", __func__,
+				urb->actual_length);
 		} else {
-			dbg(1," %s : read_buffer overflow", __FUNCTION__);
+			dev_dbg(&dev->udev->dev,"%s : read_buffer overflow\n",
+				__func__);
 		}
 	}
 
@@ -216,9 +196,6 @@ exit:
 	spin_unlock(&dev->buflock);
 	/* always wake up so we recover from errors */
 	wake_up_interruptible(&dev->read_wait);
-	adu_debug_data(5, __FUNCTION__, urb->actual_length,
-		       urb->transfer_buffer);
-	dbg(4," %s : leave, status %d", __FUNCTION__, status);
 }
 
 static void adu_interrupt_out_callback(struct urb *urb)
@@ -226,24 +203,23 @@ static void adu_interrupt_out_callback(struct urb *urb)
 	struct adu_device *dev = urb->context;
 	int status = urb->status;
 
-	dbg(4," %s : enter, status %d", __FUNCTION__, status);
-	adu_debug_data(5,__FUNCTION__, urb->actual_length, urb->transfer_buffer);
+	adu_debug_data(&dev->udev->dev, __func__,
+		       urb->actual_length, urb->transfer_buffer);
 
 	if (status != 0) {
 		if ((status != -ENOENT) &&
 		    (status != -ECONNRESET)) {
-			dbg(1, " %s :nonzero status received: %d",
-			    __FUNCTION__, status);
+			dev_dbg(&dev->udev->dev,
+				"%s :nonzero status received: %d\n", __func__,
+				status);
 		}
-		goto exit;
+		return;
 	}
 
-	wake_up_interruptible(&dev->write_wait);
-exit:
-
-	adu_debug_data(5, __FUNCTION__, urb->actual_length,
-		       urb->transfer_buffer);
-	dbg(4," %s : leave, status %d", __FUNCTION__, status);
+	spin_lock(&dev->buflock);
+	dev->out_urb_finished = 1;
+	wake_up(&dev->write_wait);
+	spin_unlock(&dev->buflock);
 }
 
 static int adu_open(struct inode *inode, struct file *file)
@@ -251,127 +227,114 @@ static int adu_open(struct inode *inode, struct file *file)
 	struct adu_device *dev = NULL;
 	struct usb_interface *interface;
 	int subminor;
-	int retval = 0;
-
-	dbg(2,"%s : enter", __FUNCTION__);
+	int retval;
 
 	subminor = iminor(inode);
 
+	retval = mutex_lock_interruptible(&adutux_mutex);
+	if (retval)
+		goto exit_no_lock;
+
 	interface = usb_find_interface(&adu_driver, subminor);
 	if (!interface) {
-		err("%s - error, can't find device for minor %d",
-		    __FUNCTION__, subminor);
+		pr_err("%s - error, can't find device for minor %d\n",
+		       __func__, subminor);
 		retval = -ENODEV;
 		goto exit_no_device;
 	}
 
 	dev = usb_get_intfdata(interface);
-	if (!dev) {
+	if (!dev || !dev->udev) {
 		retval = -ENODEV;
 		goto exit_no_device;
 	}
 
-	/* lock this device */
-	if ((retval = mutex_lock_interruptible(&dev->mtx))) {
-		dbg(2, "%s : mutex lock failed", __FUNCTION__);
+	/* check that nobody else is using the device */
+	if (dev->open_count) {
+		retval = -EBUSY;
 		goto exit_no_device;
 	}
 
-	/* increment our usage count for the device */
 	++dev->open_count;
-	dbg(2,"%s : open count %d", __FUNCTION__, dev->open_count);
+	dev_dbg(&dev->udev->dev, "%s: open count %d\n", __func__,
+		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 */
-		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->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
-		dev->read_urb_finished = 0;
-		retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
-		if (retval)
-			--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,
+			 usb_endpoint_maxp(dev->interrupt_in_endpoint),
+			 adu_interrupt_in_callback, dev,
+			 dev->interrupt_in_endpoint->bInterval);
+	dev->read_urb_finished = 0;
+	if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
+		dev->read_urb_finished = 1;
+	/* we ignore failure */
+	/* end of fixup for first read */
 
-exit_no_device:
-	dbg(2,"%s : leave, return value %d ", __FUNCTION__, retval);
+	/* initialize out direction */
+	dev->out_urb_finished = 1;
+
+	retval = 0;
 
+exit_no_device:
+	mutex_unlock(&adutux_mutex);
+exit_no_lock:
 	return retval;
 }
 
-static int adu_release_internal(struct adu_device *dev)
+static void adu_release_internal(struct adu_device *dev)
 {
-	int retval = 0;
-
-	dbg(2," %s : enter", __FUNCTION__);
-
 	/* decrement our usage count for the device */
 	--dev->open_count;
-	dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
+	dev_dbg(&dev->udev->dev, "%s : open count %d\n", __func__,
+		dev->open_count);
 	if (dev->open_count <= 0) {
 		adu_abort_transfers(dev);
 		dev->open_count = 0;
 	}
-
-	dbg(2," %s : leave", __FUNCTION__);
-	return retval;
 }
 
 static int adu_release(struct inode *inode, struct file *file)
 {
-	struct adu_device *dev = NULL;
+	struct adu_device *dev;
 	int retval = 0;
 
-	dbg(2," %s : enter", __FUNCTION__);
-
 	if (file == NULL) {
- 		dbg(1," %s : file is NULL", __FUNCTION__);
 		retval = -ENODEV;
 		goto exit;
 	}
 
 	dev = file->private_data;
-
 	if (dev == NULL) {
- 		dbg(1," %s : object is NULL", __FUNCTION__);
 		retval = -ENODEV;
 		goto exit;
 	}
 
-	/* lock our device */
-	mutex_lock(&dev->mtx); /* not interruptible */
+	mutex_lock(&adutux_mutex); /* not interruptible */
 
 	if (dev->open_count <= 0) {
-		dbg(1," %s : device not opened", __FUNCTION__);
+		dev_dbg(&dev->udev->dev, "%s : device not opened\n", __func__);
 		retval = -ENODEV;
-		goto exit;
+		goto unlock;
 	}
 
+	adu_release_internal(dev);
 	if (dev->udev == NULL) {
 		/* the device was unplugged before the file was released */
-		mutex_unlock(&dev->mtx);
-		adu_delete(dev);
-		dev = NULL;
-	} else {
-		/* do the work */
-		retval = adu_release_internal(dev);
+		if (!dev->open_count)	/* ... and we're the last user */
+			adu_delete(dev);
 	}
-
+unlock:
+	mutex_unlock(&adutux_mutex);
 exit:
-	if (dev)
-		mutex_unlock(&dev->mtx);
-	dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
 	return retval;
 }
 
@@ -388,40 +351,38 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
 	unsigned long flags;
 	DECLARE_WAITQUEUE(wait, current);
 
-	dbg(2," %s : enter, count = %Zd, file=%p", __FUNCTION__, count, file);
-
 	dev = file->private_data;
-	dbg(2," %s : dev=%p", __FUNCTION__, dev);
-	/* lock this object */
 	if (mutex_lock_interruptible(&dev->mtx))
 		return -ERESTARTSYS;
 
 	/* verify that the device wasn't unplugged */
-	if (dev->udev == NULL || dev->minor == 0) {
+	if (dev->udev == NULL) {
 		retval = -ENODEV;
-		err("No device or device unplugged %d", retval);
+		pr_err("No device or device unplugged %d\n", retval);
 		goto exit;
 	}
 
 	/* verify that some data was requested */
 	if (count == 0) {
-		dbg(1," %s : read request of 0 bytes", __FUNCTION__);
+		dev_dbg(&dev->udev->dev, "%s : read request of 0 bytes\n",
+			__func__);
 		goto exit;
 	}
 
 	timeout = COMMAND_TIMEOUT;
-	dbg(2," %s : about to start looping", __FUNCTION__);
+	dev_dbg(&dev->udev->dev, "%s : about to start looping\n", __func__);
 	while (bytes_to_read) {
 		int data_in_secondary = dev->secondary_tail - dev->secondary_head;
-		dbg(2," %s : while, data_in_secondary=%d, status=%d",
-		    __FUNCTION__, data_in_secondary,
-		    dev->interrupt_in_urb->status);
+		dev_dbg(&dev->udev->dev,
+			"%s : while, data_in_secondary=%d, status=%d\n",
+			__func__, data_in_secondary,
+			dev->interrupt_in_urb->status);
 
 		if (data_in_secondary) {
 			/* drain secondary buffer */
 			int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
 			i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
-			if (i < 0) {
+			if (i) {
 				retval = -EFAULT;
 				goto exit;
 			}
@@ -438,8 +399,9 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
 			if (dev->read_buffer_length) {
 				/* we secure access to the primary */
 				char *tmp;
-				dbg(2," %s : swap, read_buffer_length = %d",
-				    __FUNCTION__, dev->read_buffer_length);
+				dev_dbg(&dev->udev->dev,
+					"%s : swap, read_buffer_length = %d\n",
+					__func__, dev->read_buffer_length);
 				tmp = dev->read_buffer_secondary;
 				dev->read_buffer_secondary = dev->read_buffer_primary;
 				dev->read_buffer_primary = tmp;
@@ -451,33 +413,37 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
 				should_submit = 1;
 			} else {
 				/* even the primary was empty - we may need to do IO */
-				if (dev->interrupt_in_urb->status == -EINPROGRESS) {
+				if (!dev->read_urb_finished) {
 					/* somebody is doing IO */
 					spin_unlock_irqrestore(&dev->buflock, flags);
-					dbg(2," %s : submitted already", __FUNCTION__);
+					dev_dbg(&dev->udev->dev,
+						"%s : submitted already\n",
+						__func__);
 				} else {
 					/* we must initiate input */
-					dbg(2," %s : initiate input", __FUNCTION__);
+					dev_dbg(&dev->udev->dev,
+						"%s : initiate input\n",
+						__func__);
 					dev->read_urb_finished = 0;
+					spin_unlock_irqrestore(&dev->buflock, flags);
 
-					usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
-							 usb_rcvintpipe(dev->udev,
-							 		dev->interrupt_in_endpoint->bEndpointAddress),
+					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),
+							 usb_endpoint_maxp(dev->interrupt_in_endpoint),
 							 adu_interrupt_in_callback,
 							 dev,
 							 dev->interrupt_in_endpoint->bInterval);
-					retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
-					if (!retval) {
-						spin_unlock_irqrestore(&dev->buflock, flags);
-						dbg(2," %s : submitted OK", __FUNCTION__);
-					} else {
+					retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
+					if (retval) {
+						dev->read_urb_finished = 1;
 						if (retval == -ENOMEM) {
 							retval = bytes_read ? bytes_read : -ENOMEM;
 						}
-						spin_unlock_irqrestore(&dev->buflock, flags);
-						dbg(2," %s : submit failed", __FUNCTION__);
+						dev_dbg(&dev->udev->dev,
+							"%s : submit failed\n",
+							__func__);
 						goto exit;
 					}
 				}
@@ -485,20 +451,27 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
 				/* we wait for I/O to complete */
 				set_current_state(TASK_INTERRUPTIBLE);
 				add_wait_queue(&dev->read_wait, &wait);
-				if (!dev->read_urb_finished)
+				spin_lock_irqsave(&dev->buflock, flags);
+				if (!dev->read_urb_finished) {
+					spin_unlock_irqrestore(&dev->buflock, flags);
 					timeout = schedule_timeout(COMMAND_TIMEOUT);
-				else
+				} else {
+					spin_unlock_irqrestore(&dev->buflock, flags);
 					set_current_state(TASK_RUNNING);
+				}
 				remove_wait_queue(&dev->read_wait, &wait);
 
 				if (timeout <= 0) {
-					dbg(2," %s : timeout", __FUNCTION__);
+					dev_dbg(&dev->udev->dev,
+						"%s : timeout\n", __func__);
 					retval = bytes_read ? bytes_read : -ETIMEDOUT;
 					goto exit;
 				}
 
 				if (signal_pending(current)) {
-					dbg(2," %s : signal pending", __FUNCTION__);
+					dev_dbg(&dev->udev->dev,
+						"%s : signal pending\n",
+						__func__);
 					retval = bytes_read ? bytes_read : -EINTR;
 					goto exit;
 				}
@@ -508,104 +481,107 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
 
 	retval = bytes_read;
 	/* if the primary buffer is empty then use it */
-	if (should_submit && !dev->interrupt_in_urb->status==-EINPROGRESS) {
-		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->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
+	spin_lock_irqsave(&dev->buflock, flags);
+	if (should_submit && dev->read_urb_finished) {
 		dev->read_urb_finished = 0;
-		usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
+		spin_unlock_irqrestore(&dev->buflock, flags);
+		usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
+				 usb_rcvintpipe(dev->udev,
+					dev->interrupt_in_endpoint->bEndpointAddress),
+				dev->interrupt_in_buffer,
+				usb_endpoint_maxp(dev->interrupt_in_endpoint),
+				adu_interrupt_in_callback,
+				dev,
+				dev->interrupt_in_endpoint->bInterval);
+		if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
+			dev->read_urb_finished = 1;
 		/* we ignore failure */
+	} else {
+		spin_unlock_irqrestore(&dev->buflock, flags);
 	}
 
 exit:
 	/* unlock the device */
 	mutex_unlock(&dev->mtx);
 
-	dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
 	return retval;
 }
 
 static ssize_t adu_write(struct file *file, const __user char *buffer,
 			 size_t count, loff_t *ppos)
 {
+	DECLARE_WAITQUEUE(waita, current);
 	struct adu_device *dev;
 	size_t bytes_written = 0;
 	size_t bytes_to_write;
 	size_t buffer_size;
+	unsigned long flags;
 	int retval;
-	int timeout = 0;
-
-	dbg(2," %s : enter, count = %Zd", __FUNCTION__, count);
 
 	dev = file->private_data;
 
-	/* lock this object */
 	retval = mutex_lock_interruptible(&dev->mtx);
 	if (retval)
 		goto exit_nolock;
 
 	/* verify that the device wasn't unplugged */
-	if (dev->udev == NULL || dev->minor == 0) {
+	if (dev->udev == NULL) {
 		retval = -ENODEV;
-		err("No device or device unplugged %d", retval);
+		pr_err("No device or device unplugged %d\n", retval);
 		goto exit;
 	}
 
 	/* verify that we actually have some data to write */
 	if (count == 0) {
-		dbg(1," %s : write request of 0 bytes", __FUNCTION__);
+		dev_dbg(&dev->udev->dev, "%s : write request of 0 bytes\n",
+			__func__);
 		goto exit;
 	}
 
-
 	while (count > 0) {
-		if (dev->interrupt_out_urb->status == -EINPROGRESS) {
-			timeout = COMMAND_TIMEOUT;
+		add_wait_queue(&dev->write_wait, &waita);
+		set_current_state(TASK_INTERRUPTIBLE);
+		spin_lock_irqsave(&dev->buflock, flags);
+		if (!dev->out_urb_finished) {
+			spin_unlock_irqrestore(&dev->buflock, flags);
 
-			while (timeout > 0) {
-				if (signal_pending(current)) {
-				dbg(1," %s : interrupted", __FUNCTION__);
+			mutex_unlock(&dev->mtx);
+			if (signal_pending(current)) {
+				dev_dbg(&dev->udev->dev, "%s : interrupted\n",
+					__func__);
+				set_current_state(TASK_RUNNING);
 				retval = -EINTR;
-				goto exit;
+				goto exit_onqueue;
 			}
-			mutex_unlock(&dev->mtx);
-			timeout = interruptible_sleep_on_timeout(&dev->write_wait, timeout);
+			if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
+				dev_dbg(&dev->udev->dev,
+					"%s - command timed out.\n", __func__);
+				retval = -ETIMEDOUT;
+				goto exit_onqueue;
+			}
+			remove_wait_queue(&dev->write_wait, &waita);
 			retval = mutex_lock_interruptible(&dev->mtx);
 			if (retval) {
 				retval = bytes_written ? bytes_written : retval;
 				goto exit_nolock;
 			}
-			if (timeout > 0) {
-				break;
-			}
-			dbg(1," %s : interrupted timeout: %d", __FUNCTION__, timeout);
-		}
-
-
-		dbg(1," %s : final timeout: %d", __FUNCTION__, timeout);
-
-		if (timeout == 0) {
-			dbg(1, "%s - command timed out.", __FUNCTION__);
-			retval = -ETIMEDOUT;
-			goto exit;
-		}
-
-		dbg(4," %s : in progress, count = %Zd", __FUNCTION__, count);
 
+			dev_dbg(&dev->udev->dev,
+				"%s : in progress, count = %Zd\n",
+				__func__, count);
 		} else {
-			dbg(4," %s : sending, count = %Zd", __FUNCTION__, count);
+			spin_unlock_irqrestore(&dev->buflock, flags);
+			set_current_state(TASK_RUNNING);
+			remove_wait_queue(&dev->write_wait, &waita);
+			dev_dbg(&dev->udev->dev, "%s : sending, count = %Zd\n",
+				__func__, count);
 
 			/* write the data into interrupt_out_buffer from userspace */
-			buffer_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
+			buffer_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
 			bytes_to_write = count > buffer_size ? buffer_size : count;
-			dbg(4," %s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd",
-			    __FUNCTION__, buffer_size, count, bytes_to_write);
+			dev_dbg(&dev->udev->dev,
+				"%s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd\n",
+				__func__, buffer_size, count, bytes_to_write);
 
 			if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
 				retval = -EFAULT;
@@ -621,12 +597,14 @@ static ssize_t adu_write(struct file *file, const __user char *buffer,
 				bytes_to_write,
 				adu_interrupt_out_callback,
 				dev,
-				dev->interrupt_in_endpoint->bInterval);
-			/* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
+				dev->interrupt_out_endpoint->bInterval);
 			dev->interrupt_out_urb->actual_length = bytes_to_write;
+			dev->out_urb_finished = 0;
 			retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 			if (retval < 0) {
-				err("Couldn't submit interrupt_out_urb %d", retval);
+				dev->out_urb_finished = 1;
+				dev_err(&dev->udev->dev, "Couldn't submit "
+					"interrupt_out_urb %d\n", retval);
 				goto exit;
 			}
 
@@ -636,16 +614,16 @@ static ssize_t adu_write(struct file *file, const __user char *buffer,
 			bytes_written += bytes_to_write;
 		}
 	}
-
-	retval = bytes_written;
+	mutex_unlock(&dev->mtx);
+	return bytes_written;
 
 exit:
-	/* unlock the device */
 	mutex_unlock(&dev->mtx);
 exit_nolock:
+	return retval;
 
-	dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
-
+exit_onqueue:
+	remove_wait_queue(&dev->write_wait, &waita);
 	return retval;
 }
 
@@ -656,6 +634,7 @@ static const struct file_operations adu_fops = {
 	.write = adu_write,
 	.open = adu_open,
 	.release = adu_release,
+	.llseek = noop_llseek,
 };
 
 /*
@@ -686,14 +665,12 @@ static int adu_probe(struct usb_interface *interface,
 	int out_end_size;
 	int i;
 
-	dbg(2," %s : enter", __FUNCTION__);
-
 	if (udev == NULL) {
 		dev_err(&interface->dev, "udev is NULL.\n");
 		goto exit;
 	}
 
-	/* allocate memory for our device state and intialize it */
+	/* allocate memory for our device state and initialize it */
 	dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
 	if (dev == NULL) {
 		dev_err(&interface->dev, "Out of memory\n");
@@ -728,8 +705,8 @@ static int adu_probe(struct usb_interface *interface,
 		goto error;
 	}
 
-	in_end_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
-	out_end_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
+	in_end_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
+	out_end_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
 
 	dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
 	if (!dev->read_buffer_primary) {
@@ -787,7 +764,7 @@ static int adu_probe(struct usb_interface *interface,
 		dev_err(&interface->dev, "Could not retrieve serial number\n");
 		goto error;
 	}
-	dbg(2," %s : serial_number=%s", __FUNCTION__, dev->serial_number);
+	dev_dbg(&interface->dev,"serial_number=%s", dev->serial_number);
 
 	/* we can register the device now, as it is ready */
 	usb_set_intfdata(interface, dev);
@@ -804,12 +781,10 @@ static int adu_probe(struct usb_interface *interface,
 	dev->minor = interface->minor;
 
 	/* let the user know what node this device is now attached to */
-	dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d",
-		 udev->descriptor.idProduct, dev->serial_number,
+	dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
+		 le16_to_cpu(udev->descriptor.idProduct), dev->serial_number,
 		 (dev->minor - ADU_MINOR_BASE));
 exit:
-	dbg(2," %s : leave, return value %p (dev)", __FUNCTION__, dev);
-
 	return retval;
 
 error:
@@ -827,33 +802,27 @@ static void adu_disconnect(struct usb_interface *interface)
 	struct adu_device *dev;
 	int minor;
 
-	dbg(2," %s : enter", __FUNCTION__);
-
 	dev = usb_get_intfdata(interface);
-	usb_set_intfdata(interface, NULL);
 
+	mutex_lock(&dev->mtx);	/* not interruptible */
+	dev->udev = NULL;	/* poison */
 	minor = dev->minor;
-
-	/* give back our minor */
 	usb_deregister_dev(interface, &adu_class);
-	dev->minor = 0;
+	mutex_unlock(&dev->mtx);
 
-	mutex_lock(&dev->mtx); /* not interruptible */
+	mutex_lock(&adutux_mutex);
+	usb_set_intfdata(interface, NULL);
 
 	/* if the device is not opened, then we clean up right now */
-	dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
-	if (!dev->open_count) {
-		mutex_unlock(&dev->mtx);
+	dev_dbg(&dev->udev->dev, "%s : open count %d\n",
+		__func__, dev->open_count);
+	if (!dev->open_count)
 		adu_delete(dev);
-	} else {
-		dev->udev = NULL;
-		mutex_unlock(&dev->mtx);
-	}
 
-	dev_info(&interface->dev, "ADU device adutux%d now disconnected",
-		 (minor - ADU_MINOR_BASE));
+	mutex_unlock(&adutux_mutex);
 
-	dbg(2," %s : leave", __FUNCTION__);
+	dev_info(&interface->dev, "ADU device adutux%d now disconnected\n",
+		 (minor - ADU_MINOR_BASE));
 }
 
 /* usb specific object needed to register this driver with the usb subsystem */
@@ -864,39 +833,7 @@ static struct usb_driver adu_driver = {
 	.id_table = device_table,
 };
 
-static int __init adu_init(void)
-{
-	int result;
-
-	dbg(2," %s : enter", __FUNCTION__);
-
-	/* register this driver with the USB subsystem */
-	result = usb_register(&adu_driver);
-	if (result < 0) {
-		err("usb_register failed for the "__FILE__" driver. "
-		    "Error number %d", result);
-		goto exit;
-	}
-
-	info("adutux " DRIVER_DESC " " DRIVER_VERSION);
-	info("adutux is an experimental driver. Use at your own risk");
-
-exit:
-	dbg(2," %s : leave, return value %d", __FUNCTION__, result);
-
-	return result;
-}
-
-static void __exit adu_exit(void)
-{
-	dbg(2," %s : enter", __FUNCTION__);
-	/* deregister this driver with the USB subsystem */
-	usb_deregister(&adu_driver);
-	dbg(2," %s : leave", __FUNCTION__);
-}
-
-module_init(adu_init);
-module_exit(adu_exit);
+module_usb_driver(adu_driver);
 
 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);