3 files changed, 302 insertions, 77 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 63c34043b4d..c257453fa9d 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -51,6 +51,7 @@
  */
 
 #undef DEBUG
+#undef VERBOSE_DEBUG
 
 #include <linux/kernel.h>
 #include <linux/errno.h>
@@ -70,6 +71,9 @@
 
 #include "cdc-acm.h"
 
+
+#define ACM_CLOSE_TIMEOUT	15	/* seconds to let writes drain */
+
 /*
  * Version Information
  */
@@ -85,6 +89,12 @@ static DEFINE_MUTEX(open_mutex);
 
 #define ACM_READY(acm)	(acm && acm->dev && acm->used)
 
+#ifdef VERBOSE_DEBUG
+#define verbose	1
+#else
+#define verbose	0
+#endif
+
 /*
  * Functions for ACM control messages.
  */
@@ -136,19 +146,17 @@ static int acm_wb_alloc(struct acm *acm)
 static int acm_wb_is_avail(struct acm *acm)
 {
 	int i, n;
+	unsigned long flags;
 
 	n = ACM_NW;
+	spin_lock_irqsave(&acm->write_lock, flags);
 	for (i = 0; i < ACM_NW; i++) {
 		n -= acm->wb[i].use;
 	}
+	spin_unlock_irqrestore(&acm->write_lock, flags);
 	return n;
 }
 
-static inline int acm_wb_is_used(struct acm *acm, int wbn)
-{
-	return acm->wb[wbn].use;
-}
-
 /*
  * Finish write.
  */
@@ -157,51 +165,62 @@ static void acm_write_done(struct acm *acm, struct acm_wb *wb)
 	unsigned long flags;
 
 	spin_lock_irqsave(&acm->write_lock, flags);
-	acm->write_ready = 1;
 	wb->use = 0;
+	acm->transmitting--;
 	spin_unlock_irqrestore(&acm->write_lock, flags);
 }
 
 /*
  * Poke write.
+ *
+ * the caller is responsible for locking
  */
+
+static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
+{
+	int rc;
+
+	acm->transmitting++;
+
+	wb->urb->transfer_buffer = wb->buf;
+	wb->urb->transfer_dma = wb->dmah;
+	wb->urb->transfer_buffer_length = wb->len;
+	wb->urb->dev = acm->dev;
+
+	if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
+		dbg("usb_submit_urb(write bulk) failed: %d", rc);
+		acm_write_done(acm, wb);
+	}
+	return rc;
+}
+
 static int acm_write_start(struct acm *acm, int wbn)
 {
 	unsigned long flags;
-	struct acm_wb *wb;
+	struct acm_wb *wb = &acm->wb[wbn];
 	int rc;
 
 	spin_lock_irqsave(&acm->write_lock, flags);
 	if (!acm->dev) {
+		wb->use = 0;
 		spin_unlock_irqrestore(&acm->write_lock, flags);
 		return -ENODEV;
 	}
 
-	if (!acm->write_ready) {
+	dbg("%s susp_count: %d", __func__, acm->susp_count);
+	if (acm->susp_count) {
+		acm->delayed_wb = wb;
+		schedule_work(&acm->waker);
 		spin_unlock_irqrestore(&acm->write_lock, flags);
 		return 0;	/* A white lie */
 	}
+	usb_mark_last_busy(acm->dev);
 
-	if (!acm_wb_is_used(acm, wbn)) {
-		spin_unlock_irqrestore(&acm->write_lock, flags);
-		return 0;
-	}
-	wb = &acm->wb[wbn];
-
-	if(acm_wb_is_avail(acm) <= 1)
-		acm->write_ready = 0;
+	rc = acm_start_wb(acm, wb);
 	spin_unlock_irqrestore(&acm->write_lock, flags);
 
-	wb->urb->transfer_buffer = wb->buf;
-	wb->urb->transfer_dma = wb->dmah;
-	wb->urb->transfer_buffer_length = wb->len;
-	wb->urb->dev = acm->dev;
-
-	if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
-		dbg("usb_submit_urb(write bulk) failed: %d", rc);
-		acm_write_done(acm, wb);
-	}
 	return rc;
+
 }
 /*
  * attributes exported through sysfs
@@ -304,6 +323,7 @@ static void acm_ctrl_irq(struct urb *urb)
 			break;
 	}
 exit:
+	usb_mark_last_busy(acm->dev);
 	retval = usb_submit_urb (urb, GFP_ATOMIC);
 	if (retval)
 		err ("%s - usb_submit_urb failed with result %d",
@@ -320,8 +340,11 @@ static void acm_read_bulk(struct urb *urb)
 
 	dbg("Entering acm_read_bulk with status %d", status);
 
-	if (!ACM_READY(acm))
+	if (!ACM_READY(acm)) {
+		dev_dbg(&acm->data->dev, "Aborting, acm not ready");
 		return;
+	}
+	usb_mark_last_busy(acm->dev);
 
 	if (status)
 		dev_dbg(&acm->data->dev, "bulk rx status %d\n", status);
@@ -331,6 +354,7 @@ static void acm_read_bulk(struct urb *urb)
 
 	if (likely(status == 0)) {
 		spin_lock(&acm->read_lock);
+		acm->processing++;
 		list_add_tail(&rcv->list, &acm->spare_read_urbs);
 		list_add_tail(&buf->list, &acm->filled_read_bufs);
 		spin_unlock(&acm->read_lock);
@@ -343,7 +367,8 @@ static void acm_read_bulk(struct urb *urb)
 		/* nevertheless the tasklet must be kicked unconditionally
 		so the queue cannot dry up */
 	}
-	tasklet_schedule(&acm->urb_task);
+	if (likely(!acm->susp_count))
+		tasklet_schedule(&acm->urb_task);
 }
 
 static void acm_rx_tasklet(unsigned long _acm)
@@ -354,16 +379,23 @@ static void acm_rx_tasklet(unsigned long _acm)
 	struct acm_ru *rcv;
 	unsigned long flags;
 	unsigned char throttled;
+
 	dbg("Entering acm_rx_tasklet");
 
 	if (!ACM_READY(acm))
+	{
+		dbg("acm_rx_tasklet: ACM not ready");
 		return;
+	}
 
 	spin_lock_irqsave(&acm->throttle_lock, flags);
 	throttled = acm->throttle;
 	spin_unlock_irqrestore(&acm->throttle_lock, flags);
 	if (throttled)
+	{
+		dbg("acm_rx_tasklet: throttled");
 		return;
+	}
 
 next_buffer:
 	spin_lock_irqsave(&acm->read_lock, flags);
@@ -403,6 +435,7 @@ urbs:
 	while (!list_empty(&acm->spare_read_bufs)) {
 		spin_lock_irqsave(&acm->read_lock, flags);
 		if (list_empty(&acm->spare_read_urbs)) {
+			acm->processing = 0;
 			spin_unlock_irqrestore(&acm->read_lock, flags);
 			return;
 		}
@@ -425,44 +458,72 @@ urbs:
 		rcv->urb->transfer_dma = buf->dma;
 		rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 
-		dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
-
 		/* This shouldn't kill the driver as unsuccessful URBs are returned to the
 		   free-urbs-pool and resubmited ASAP */
-		if (usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
+		spin_lock_irqsave(&acm->read_lock, flags);
+		if (acm->susp_count || usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
 			list_add(&buf->list, &acm->spare_read_bufs);
-			spin_lock_irqsave(&acm->read_lock, flags);
 			list_add(&rcv->list, &acm->spare_read_urbs);
+			acm->processing = 0;
 			spin_unlock_irqrestore(&acm->read_lock, flags);
 			return;
+		} else {
+			spin_unlock_irqrestore(&acm->read_lock, flags);
+			dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
 		}
 	}
+	spin_lock_irqsave(&acm->read_lock, flags);
+	acm->processing = 0;
+	spin_unlock_irqrestore(&acm->read_lock, flags);
 }
 
 /* data interface wrote those outgoing bytes */
 static void acm_write_bulk(struct urb *urb)
 {
-	struct acm *acm;
 	struct acm_wb *wb = urb->context;
+	struct acm *acm = wb->instance;
 
-	dbg("Entering acm_write_bulk with status %d", urb->status);
+	if (verbose || urb->status
+			|| (urb->actual_length != urb->transfer_buffer_length))
+		dev_dbg(&acm->data->dev, "tx %d/%d bytes -- > %d\n",
+			urb->actual_length,
+			urb->transfer_buffer_length,
+			urb->status);
 
-	acm = wb->instance;
 	acm_write_done(acm, wb);
 	if (ACM_READY(acm))
 		schedule_work(&acm->work);
+	else
+		wake_up_interruptible(&acm->drain_wait);
 }
 
 static void acm_softint(struct work_struct *work)
 {
 	struct acm *acm = container_of(work, struct acm, work);
-	dbg("Entering acm_softint.");
-	
+
+	dev_vdbg(&acm->data->dev, "tx work\n");
 	if (!ACM_READY(acm))
 		return;
 	tty_wakeup(acm->tty);
 }
 
+static void acm_waker(struct work_struct *waker)
+{
+	struct acm *acm = container_of(waker, struct acm, waker);
+	int rv;
+
+	rv = usb_autopm_get_interface(acm->control);
+	if (rv < 0) {
+		err("Autopm failure in %s", __func__);
+		return;
+	}
+	if (acm->delayed_wb) {
+		acm_start_wb(acm, acm->delayed_wb);
+		acm->delayed_wb = NULL;
+	}
+	usb_autopm_put_interface(acm->control);
+}
+
 /*
  * TTY handlers
  */
@@ -492,6 +553,8 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
 
 	if (usb_autopm_get_interface(acm->control) < 0)
 		goto early_bail;
+	else
+		acm->control->needs_remote_wakeup = 1;
 
 	mutex_lock(&acm->mutex);
 	if (acm->used++) {
@@ -509,6 +572,7 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
 	if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) &&
 	    (acm->ctrl_caps & USB_CDC_CAP_LINE))
 		goto full_bailout;
+	usb_autopm_put_interface(acm->control);
 
 	INIT_LIST_HEAD(&acm->spare_read_urbs);
 	INIT_LIST_HEAD(&acm->spare_read_bufs);
@@ -525,8 +589,8 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
 	tasklet_schedule(&acm->urb_task);
 
 done:
-err_out:
 	mutex_unlock(&acm->mutex);
+err_out:
 	mutex_unlock(&open_mutex);
 	return rv;
 
@@ -558,6 +622,8 @@ static void acm_tty_unregister(struct acm *acm)
 	kfree(acm);
 }
 
+static int acm_tty_chars_in_buffer(struct tty_struct *tty);
+
 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 {
 	struct acm *acm = tty->driver_data;
@@ -570,12 +636,21 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 	mutex_lock(&open_mutex);
 	if (!--acm->used) {
 		if (acm->dev) {
+			usb_autopm_get_interface(acm->control);
 			acm_set_control(acm, acm->ctrlout = 0);
+
+			/* try letting the last writes drain naturally */
+			wait_event_interruptible_timeout(acm->drain_wait,
+					(ACM_NW == acm_wb_is_avail(acm))
+						|| !acm->dev,
+					ACM_CLOSE_TIMEOUT * HZ);
+
 			usb_kill_urb(acm->ctrlurb);
 			for (i = 0; i < ACM_NW; i++)
 				usb_kill_urb(acm->wb[i].urb);
 			for (i = 0; i < nr; i++)
 				usb_kill_urb(acm->ru[i].urb);
+			acm->control->needs_remote_wakeup = 0;
 			usb_autopm_put_interface(acm->control);
 		} else
 			acm_tty_unregister(acm);
@@ -625,7 +700,7 @@ static int acm_tty_write_room(struct tty_struct *tty)
 	 * Do not let the line discipline to know that we have a reserve,
 	 * or it might get too enthusiastic.
 	 */
-	return (acm->write_ready && acm_wb_is_avail(acm)) ? acm->writesize : 0;
+	return acm_wb_is_avail(acm) ? acm->writesize : 0;
 }
 
 static int acm_tty_chars_in_buffer(struct tty_struct *tty)
@@ -660,13 +735,16 @@ static void acm_tty_unthrottle(struct tty_struct *tty)
 	tasklet_schedule(&acm->urb_task);
 }
 
-static void acm_tty_break_ctl(struct tty_struct *tty, int state)
+static int acm_tty_break_ctl(struct tty_struct *tty, int state)
 {
 	struct acm *acm = tty->driver_data;
+	int retval;
 	if (!ACM_READY(acm))
-		return;
-	if (acm_send_break(acm, state ? 0xffff : 0))
+		return -EINVAL;
+	retval = acm_send_break(acm, state ? 0xffff : 0);
+	if (retval < 0)
 		dbg("send break failed");
+	return retval;
 }
 
 static int acm_tty_tiocmget(struct tty_struct *tty, struct file *file)
@@ -766,7 +844,7 @@ static void acm_tty_set_termios(struct tty_struct *tty, struct ktermios *termios
  * USB probe and disconnect routines.
  */
 
-/* Little helper: write buffers free */
+/* Little helpers: write/read buffers free */
 static void acm_write_buffers_free(struct acm *acm)
 {
 	int i;
@@ -777,6 +855,15 @@ static void acm_write_buffers_free(struct acm *acm)
 	}
 }
 
+static void acm_read_buffers_free(struct acm *acm)
+{
+	struct usb_device *usb_dev = interface_to_usbdev(acm->control);
+	int i, n = acm->rx_buflimit;
+
+	for (i = 0; i < n; i++)
+		usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
+}
+
 /* Little helper: write buffers allocate */
 static int acm_write_buffers_alloc(struct acm *acm)
 {
@@ -987,11 +1074,12 @@ skip_normal_probe:
 	acm->urb_task.func = acm_rx_tasklet;
 	acm->urb_task.data = (unsigned long) acm;
 	INIT_WORK(&acm->work, acm_softint);
+	INIT_WORK(&acm->waker, acm_waker);
+	init_waitqueue_head(&acm->drain_wait);
 	spin_lock_init(&acm->throttle_lock);
 	spin_lock_init(&acm->write_lock);
 	spin_lock_init(&acm->read_lock);
 	mutex_init(&acm->mutex);
-	acm->write_ready = 1;
 	acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
 
 	buf = usb_buffer_alloc(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
@@ -1023,9 +1111,11 @@ skip_normal_probe:
 		rcv->instance = acm;
 	}
 	for (i = 0; i < num_rx_buf; i++) {
-		struct acm_rb *buf = &(acm->rb[i]);
+		struct acm_rb *rb = &(acm->rb[i]);
 
-		if (!(buf->base = usb_buffer_alloc(acm->dev, readsize, GFP_KERNEL, &buf->dma))) {
+		rb->base = usb_buffer_alloc(acm->dev, readsize,
+				GFP_KERNEL, &rb->dma);
+		if (!rb->base) {
 			dev_dbg(&intf->dev, "out of memory (read bufs usb_buffer_alloc)\n");
 			goto alloc_fail7;
 		}
@@ -1087,6 +1177,7 @@ skip_countries:
 	acm_set_line(acm, &acm->line);
 
 	usb_driver_claim_interface(&acm_driver, data_interface, acm);
+	usb_set_intfdata(data_interface, acm);
 
 	usb_get_intf(control_interface);
 	tty_register_device(acm_tty_driver, minor, &control_interface->dev);
@@ -1098,8 +1189,7 @@ alloc_fail8:
 	for (i = 0; i < ACM_NW; i++)
 		usb_free_urb(acm->wb[i].urb);
 alloc_fail7:
-	for (i = 0; i < num_rx_buf; i++)
-		usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
+	acm_read_buffers_free(acm);
 	for (i = 0; i < num_rx_buf; i++)
 		usb_free_urb(acm->ru[i].urb);
 	usb_free_urb(acm->ctrlurb);
@@ -1116,6 +1206,7 @@ alloc_fail:
 static void stop_data_traffic(struct acm *acm)
 {
 	int i;
+	dbg("Entering stop_data_traffic");
 
 	tasklet_disable(&acm->urb_task);
 
@@ -1125,30 +1216,22 @@ static void stop_data_traffic(struct acm *acm)
 	for (i = 0; i < acm->rx_buflimit; i++)
 		usb_kill_urb(acm->ru[i].urb);
 
-	INIT_LIST_HEAD(&acm->filled_read_bufs);
-	INIT_LIST_HEAD(&acm->spare_read_bufs);
-
 	tasklet_enable(&acm->urb_task);
 
 	cancel_work_sync(&acm->work);
+	cancel_work_sync(&acm->waker);
 }
 
 static void acm_disconnect(struct usb_interface *intf)
 {
 	struct acm *acm = usb_get_intfdata(intf);
 	struct usb_device *usb_dev = interface_to_usbdev(intf);
-	int i;
 
-	if (!acm || !acm->dev) {
-		dbg("disconnect on nonexisting interface");
+	/* sibling interface is already cleaning up */
+	if (!acm)
 		return;
-	}
 
 	mutex_lock(&open_mutex);
-	if (!usb_get_intfdata(intf)) {
-		mutex_unlock(&open_mutex);
-		return;
-	}
 	if (acm->country_codes){
 		device_remove_file(&acm->control->dev,
 				&dev_attr_wCountryCodes);
@@ -1164,10 +1247,10 @@ static void acm_disconnect(struct usb_interface *intf)
 
 	acm_write_buffers_free(acm);
 	usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
-	for (i = 0; i < acm->rx_buflimit; i++)
-		usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
+	acm_read_buffers_free(acm);
 
-	usb_driver_release_interface(&acm_driver, intf == acm->control ? acm->data : intf);
+	usb_driver_release_interface(&acm_driver, intf == acm->control ?
+					acm->data : acm->control);
 
 	if (!acm->used) {
 		acm_tty_unregister(acm);
@@ -1181,11 +1264,31 @@ static void acm_disconnect(struct usb_interface *intf)
 		tty_hangup(acm->tty);
 }
 
+#ifdef CONFIG_PM
 static int acm_suspend(struct usb_interface *intf, pm_message_t message)
 {
 	struct acm *acm = usb_get_intfdata(intf);
+	int cnt;
+
+	if (acm->dev->auto_pm) {
+		int b;
+
+		spin_lock_irq(&acm->read_lock);
+		spin_lock(&acm->write_lock);
+		b = acm->processing + acm->transmitting;
+		spin_unlock(&acm->write_lock);
+		spin_unlock_irq(&acm->read_lock);
+		if (b)
+			return -EBUSY;
+	}
 
-	if (acm->susp_count++)
+	spin_lock_irq(&acm->read_lock);
+	spin_lock(&acm->write_lock);
+	cnt = acm->susp_count++;
+	spin_unlock(&acm->write_lock);
+	spin_unlock_irq(&acm->read_lock);
+
+	if (cnt)
 		return 0;
 	/*
 	we treat opened interfaces differently,
@@ -1204,15 +1307,21 @@ static int acm_resume(struct usb_interface *intf)
 {
 	struct acm *acm = usb_get_intfdata(intf);
 	int rv = 0;
+	int cnt;
+
+	spin_lock_irq(&acm->read_lock);
+	acm->susp_count -= 1;
+	cnt = acm->susp_count;
+	spin_unlock_irq(&acm->read_lock);
 
-	if (--acm->susp_count)
+	if (cnt)
 		return 0;
 
 	mutex_lock(&acm->mutex);
 	if (acm->used) {
 		rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
 		if (rv < 0)
-		goto err_out;
+			goto err_out;
 
 		tasklet_schedule(&acm->urb_task);
 	}
@@ -1221,6 +1330,8 @@ err_out:
 	mutex_unlock(&acm->mutex);
 	return rv;
 }
+
+#endif /* CONFIG_PM */
 /*
  * USB driver structure.
  */
@@ -1251,6 +1362,9 @@ static struct usb_device_id acm_ids[] = {
 	{ USB_DEVICE(0x0803, 0x3095), /* Zoom Telephonics Model 3095F USB MODEM */
 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
 	},
+	{ USB_DEVICE(0x0572, 0x1321), /* Conexant USB MODEM CX93010 */
+	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
+	},
 
 	/* control interfaces with various AT-command sets */
 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
@@ -1276,10 +1390,14 @@ static struct usb_driver acm_driver = {
 	.name =		"cdc_acm",
 	.probe =	acm_probe,
 	.disconnect =	acm_disconnect,
+#ifdef CONFIG_PM
 	.suspend =	acm_suspend,
 	.resume =	acm_resume,
+#endif
 	.id_table =	acm_ids,
+#ifdef CONFIG_PM
 	.supports_autosuspend = 1,
+#endif
 };
 
 /*
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index 046e064b033..1f95e7aa1b6 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -106,11 +106,14 @@ struct acm {
 	struct list_head spare_read_bufs;
 	struct list_head filled_read_bufs;
 	int write_used;					/* number of non-empty write buffers */
-	int write_ready;				/* write urb is not running */
+	int processing;
+	int transmitting;
 	spinlock_t write_lock;
 	struct mutex mutex;
 	struct usb_cdc_line_coding line;		/* bits, stop, parity */
 	struct work_struct work;			/* work queue entry for line discipline waking up */
+	struct work_struct waker;
+	wait_queue_head_t drain_wait;			/* close processing */
 	struct tasklet_struct urb_task;                 /* rx processing */
 	spinlock_t throttle_lock;			/* synchronize throtteling and read callback */
 	unsigned int ctrlin;				/* input control lines (DCD, DSR, RI, break, overruns) */
@@ -123,6 +126,7 @@ struct acm {
 	unsigned char clocal;				/* termios CLOCAL */
 	unsigned int ctrl_caps;				/* control capabilities from the class specific header */
 	unsigned int susp_count;			/* number of suspended interfaces */
+	struct acm_wb *delayed_wb;			/* write queued for a device about to be woken */
 };
 
 #define CDC_DATA_INTERFACE_TYPE	0x0a
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 731db051070..7e8e1235e4e 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -28,8 +28,9 @@
 /*
  * Version Information
  */
-#define DRIVER_VERSION "v0.02"
+#define DRIVER_VERSION "v0.03"
 #define DRIVER_AUTHOR "Oliver Neukum"
+#define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
 
 static struct usb_device_id wdm_ids[] = {
 	{
@@ -87,6 +88,7 @@ struct wdm_device {
 	dma_addr_t		ihandle;
 	struct mutex		wlock;
 	struct mutex		rlock;
+	struct mutex		plock;
 	wait_queue_head_t	wait;
 	struct work_struct	rxwork;
 	int			werr;
@@ -205,7 +207,7 @@ static void wdm_int_callback(struct urb *urb)
 	req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
 	req->wValue = 0;
 	req->wIndex = desc->inum;
-	req->wLength = cpu_to_le16(desc->bMaxPacketSize0);
+	req->wLength = cpu_to_le16(desc->wMaxCommand);
 
 	usb_fill_control_urb(
 		desc->response,
@@ -214,7 +216,7 @@ static void wdm_int_callback(struct urb *urb)
 		usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
 		(unsigned char *)req,
 		desc->inbuf,
-		desc->bMaxPacketSize0,
+		desc->wMaxCommand,
 		wdm_in_callback,
 		desc
 	);
@@ -247,6 +249,7 @@ exit:
 
 static void kill_urbs(struct wdm_device *desc)
 {
+	/* the order here is essential */
 	usb_kill_urb(desc->command);
 	usb_kill_urb(desc->validity);
 	usb_kill_urb(desc->response);
@@ -266,7 +269,7 @@ static void cleanup(struct wdm_device *desc)
 			desc->sbuf,
 			desc->validity->transfer_dma);
 	usb_buffer_free(interface_to_usbdev(desc->intf),
-			desc->wMaxPacketSize,
+			desc->wMaxCommand,
 			desc->inbuf,
 			desc->response->transfer_dma);
 	kfree(desc->orq);
@@ -299,6 +302,9 @@ static ssize_t wdm_write
 	if (r)
 		goto outnl;
 
+	r = usb_autopm_get_interface(desc->intf);
+	if (r < 0)
+		goto outnp;
 	r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 							   &desc->flags));
 	if (r < 0)
@@ -347,11 +353,14 @@ static ssize_t wdm_write
 	if (rv < 0) {
 		kfree(buf);
 		clear_bit(WDM_IN_USE, &desc->flags);
+		err("Tx URB error: %d", rv);
 	} else {
 		dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 			req->wIndex);
 	}
 out:
+	usb_autopm_put_interface(desc->intf);
+outnp:
 	mutex_unlock(&desc->wlock);
 outnl:
 	return rv < 0 ? rv : count;
@@ -376,6 +385,11 @@ retry:
 		rv = wait_event_interruptible(desc->wait,
 					      test_bit(WDM_READ, &desc->flags));
 
+		if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
+			rv = -ENODEV;
+			goto err;
+		}
+		usb_mark_last_busy(interface_to_usbdev(desc->intf));
 		if (rv < 0) {
 			rv = -ERESTARTSYS;
 			goto err;
@@ -418,6 +432,9 @@ retry:
 		desc->ubuf[i] = desc->ubuf[i + cntr];
 
 	desc->length -= cntr;
+	/* in case we had outstanding data */
+	if (!desc->length)
+		clear_bit(WDM_READ, &desc->flags);
 	rv = cntr;
 
 err:
@@ -480,18 +497,28 @@ static int wdm_open(struct inode *inode, struct file *file)
 	if (test_bit(WDM_DISCONNECTING, &desc->flags))
 		goto out;
 
-	desc->count++;
+	;
 	file->private_data = desc;
 
-	rv = usb_submit_urb(desc->validity, GFP_KERNEL);
-
+	rv = usb_autopm_get_interface(desc->intf);
 	if (rv < 0) {
-		desc->count--;
-		err("Error submitting int urb - %d", rv);
+		err("Error autopm - %d", rv);
 		goto out;
 	}
-	rv = 0;
+	intf->needs_remote_wakeup = 1;
 
+	mutex_lock(&desc->plock);
+	if (!desc->count++) {
+		rv = usb_submit_urb(desc->validity, GFP_KERNEL);
+		if (rv < 0) {
+			desc->count--;
+			err("Error submitting int urb - %d", rv);
+		}
+	} else {
+		rv = 0;
+	}
+	mutex_unlock(&desc->plock);
+	usb_autopm_put_interface(desc->intf);
 out:
 	mutex_unlock(&wdm_mutex);
 	return rv;
@@ -502,10 +529,15 @@ static int wdm_release(struct inode *inode, struct file *file)
 	struct wdm_device *desc = file->private_data;
 
 	mutex_lock(&wdm_mutex);
+	mutex_lock(&desc->plock);
 	desc->count--;
+	mutex_unlock(&desc->plock);
+
 	if (!desc->count) {
 		dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
 		kill_urbs(desc);
+		if (!test_bit(WDM_DISCONNECTING, &desc->flags))
+			desc->intf->needs_remote_wakeup = 0;
 	}
 	mutex_unlock(&wdm_mutex);
 	return 0;
@@ -597,6 +629,7 @@ next_desc:
 		goto out;
 	mutex_init(&desc->wlock);
 	mutex_init(&desc->rlock);
+	mutex_init(&desc->plock);
 	spin_lock_init(&desc->iuspin);
 	init_waitqueue_head(&desc->wait);
 	desc->wMaxCommand = maxcom;
@@ -698,6 +731,7 @@ static void wdm_disconnect(struct usb_interface *intf)
 	spin_lock_irqsave(&desc->iuspin, flags);
 	set_bit(WDM_DISCONNECTING, &desc->flags);
 	set_bit(WDM_READ, &desc->flags);
+	/* to terminate pending flushes */
 	clear_bit(WDM_IN_USE, &desc->flags);
 	spin_unlock_irqrestore(&desc->iuspin, flags);
 	cancel_work_sync(&desc->rxwork);
@@ -708,11 +742,81 @@ static void wdm_disconnect(struct usb_interface *intf)
 	mutex_unlock(&wdm_mutex);
 }
 
+static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct wdm_device *desc = usb_get_intfdata(intf);
+	int rv = 0;
+
+	dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
+
+	mutex_lock(&desc->plock);
+#ifdef CONFIG_PM
+	if (interface_to_usbdev(desc->intf)->auto_pm && test_bit(WDM_IN_USE, &desc->flags)) {
+		rv = -EBUSY;
+	} else {
+#endif
+		cancel_work_sync(&desc->rxwork);
+		kill_urbs(desc);
+#ifdef CONFIG_PM
+	}
+#endif
+	mutex_unlock(&desc->plock);
+
+	return rv;
+}
+
+static int recover_from_urb_loss(struct wdm_device *desc)
+{
+	int rv = 0;
+
+	if (desc->count) {
+		rv = usb_submit_urb(desc->validity, GFP_NOIO);
+		if (rv < 0)
+			err("Error resume submitting int urb - %d", rv);
+	}
+	return rv;
+}
+static int wdm_resume(struct usb_interface *intf)
+{
+	struct wdm_device *desc = usb_get_intfdata(intf);
+	int rv;
+
+	dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
+	mutex_lock(&desc->plock);
+	rv = recover_from_urb_loss(desc);
+	mutex_unlock(&desc->plock);
+	return rv;
+}
+
+static int wdm_pre_reset(struct usb_interface *intf)
+{
+	struct wdm_device *desc = usb_get_intfdata(intf);
+
+	mutex_lock(&desc->plock);
+	return 0;
+}
+
+static int wdm_post_reset(struct usb_interface *intf)
+{
+	struct wdm_device *desc = usb_get_intfdata(intf);
+	int rv;
+
+	rv = recover_from_urb_loss(desc);
+	mutex_unlock(&desc->plock);
+	return 0;
+}
+
 static struct usb_driver wdm_driver = {
 	.name =		"cdc_wdm",
 	.probe =	wdm_probe,
 	.disconnect =	wdm_disconnect,
+	.suspend =	wdm_suspend,
+	.resume =	wdm_resume,
+	.reset_resume =	wdm_resume,
+	.pre_reset =	wdm_pre_reset,
+	.post_reset =	wdm_post_reset,
 	.id_table =	wdm_ids,
+	.supports_autosuspend = 1,
 };
 
 /* --- low level module stuff --- */
@@ -735,6 +839,5 @@ module_init(wdm_init);
 module_exit(wdm_exit);
 
 MODULE_AUTHOR(DRIVER_AUTHOR);
-MODULE_DESCRIPTION("USB Abstract Control Model driver for "
-		   "USB WCM Device Management");
+MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");