1 files changed, 78 insertions, 56 deletions

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 18aafcb..189141c 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -52,7 +52,8 @@ MODULE_DEVICE_TABLE (usb, wdm_ids);
 #define WDM_READ		4
 #define WDM_INT_STALL		5
 #define WDM_POLL_RUNNING	6
-
+#define WDM_RESPONDING		7
+#define WDM_SUSPENDING		8
 
 #define WDM_MAX			16
 
@@ -87,9 +88,7 @@ struct wdm_device {
 	int			count;
 	dma_addr_t		shandle;
 	dma_addr_t		ihandle;
-	struct mutex		wlock;
-	struct mutex		rlock;
-	struct mutex		plock;
+	struct mutex		lock;
 	wait_queue_head_t	wait;
 	struct work_struct	rxwork;
 	int			werr;
@@ -117,21 +116,22 @@ static void wdm_in_callback(struct urb *urb)
 	int status = urb->status;
 
 	spin_lock(&desc->iuspin);
+	clear_bit(WDM_RESPONDING, &desc->flags);
 
 	if (status) {
 		switch (status) {
 		case -ENOENT:
 			dev_dbg(&desc->intf->dev,
 				"nonzero urb status received: -ENOENT");
-			break;
+			goto skip_error;
 		case -ECONNRESET:
 			dev_dbg(&desc->intf->dev,
 				"nonzero urb status received: -ECONNRESET");
-			break;
+			goto skip_error;
 		case -ESHUTDOWN:
 			dev_dbg(&desc->intf->dev,
 				"nonzero urb status received: -ESHUTDOWN");
-			break;
+			goto skip_error;
 		case -EPIPE:
 			dev_err(&desc->intf->dev,
 				"nonzero urb status received: -EPIPE\n");
@@ -147,6 +147,7 @@ static void wdm_in_callback(struct urb *urb)
 	desc->reslength = urb->actual_length;
 	memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
 	desc->length += desc->reslength;
+skip_error:
 	wake_up(&desc->wait);
 
 	set_bit(WDM_READ, &desc->flags);
@@ -229,13 +230,16 @@ static void wdm_int_callback(struct urb *urb)
 	desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 	spin_lock(&desc->iuspin);
 	clear_bit(WDM_READ, &desc->flags);
-	if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
+	set_bit(WDM_RESPONDING, &desc->flags);
+	if (!test_bit(WDM_DISCONNECTING, &desc->flags)
+		&& !test_bit(WDM_SUSPENDING, &desc->flags)) {
 		rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 		dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
 			__func__, rv);
 	}
 	spin_unlock(&desc->iuspin);
 	if (rv < 0) {
+		clear_bit(WDM_RESPONDING, &desc->flags);
 		if (rv == -EPERM)
 			return;
 		if (rv == -ENOMEM) {
@@ -305,14 +309,38 @@ static ssize_t wdm_write
 	if (we < 0)
 		return -EIO;
 
-	r = mutex_lock_interruptible(&desc->wlock); /* concurrent writes */
+	desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
+	if (!buf) {
+		rv = -ENOMEM;
+		goto outnl;
+	}
+
+	r = copy_from_user(buf, buffer, count);
+	if (r > 0) {
+		kfree(buf);
+		rv = -EFAULT;
+		goto outnl;
+	}
+
+	/* concurrent writes and disconnect */
+	r = mutex_lock_interruptible(&desc->lock);
 	rv = -ERESTARTSYS;
-	if (r)
+	if (r) {
+		kfree(buf);
 		goto outnl;
+	}
+
+	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
+		kfree(buf);
+		rv = -ENODEV;
+		goto outnp;
+	}
 
 	r = usb_autopm_get_interface(desc->intf);
-	if (r < 0)
+	if (r < 0) {
+		kfree(buf);
 		goto outnp;
+	}
 
 	if (!file->f_flags && O_NONBLOCK)
 		r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
@@ -320,24 +348,8 @@ static ssize_t wdm_write
 	else
 		if (test_bit(WDM_IN_USE, &desc->flags))
 			r = -EAGAIN;
-	if (r < 0)
-		goto out;
-
-	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
-		rv = -ENODEV;
-		goto out;
-	}
-
-	desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
-	if (!buf) {
-		rv = -ENOMEM;
-		goto out;
-	}
-
-	r = copy_from_user(buf, buffer, count);
-	if (r > 0) {
+	if (r < 0) {
 		kfree(buf);
-		rv = -EFAULT;
 		goto out;
 	}
 
@@ -374,7 +386,7 @@ static ssize_t wdm_write
 out:
 	usb_autopm_put_interface(desc->intf);
 outnp:
-	mutex_unlock(&desc->wlock);
+	mutex_unlock(&desc->lock);
 outnl:
 	return rv < 0 ? rv : count;
 }
@@ -387,7 +399,7 @@ static ssize_t wdm_read
 	struct wdm_device *desc = file->private_data;
 
 
-	rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
+	rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
 	if (rv < 0)
 		return -ERESTARTSYS;
 
@@ -424,11 +436,8 @@ retry:
 		spin_lock_irq(&desc->iuspin);
 
 		if (desc->rerr) { /* read completed, error happened */
-			int t = desc->rerr;
 			desc->rerr = 0;
 			spin_unlock_irq(&desc->iuspin);
-			dev_err(&desc->intf->dev,
-				"reading had resulted in %d\n", t);
 			rv = -EIO;
 			goto err;
 		}
@@ -465,9 +474,7 @@ retry:
 	rv = cntr;
 
 err:
-	mutex_unlock(&desc->rlock);
-	if (rv < 0 && rv != -EAGAIN)
-		dev_err(&desc->intf->dev, "wdm_read: exit error\n");
+	mutex_unlock(&desc->lock);
 	return rv;
 }
 
@@ -533,7 +540,7 @@ static int wdm_open(struct inode *inode, struct file *file)
 	}
 	intf->needs_remote_wakeup = 1;
 
-	mutex_lock(&desc->plock);
+	mutex_lock(&desc->lock);
 	if (!desc->count++) {
 		rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 		if (rv < 0) {
@@ -544,7 +551,7 @@ static int wdm_open(struct inode *inode, struct file *file)
 	} else {
 		rv = 0;
 	}
-	mutex_unlock(&desc->plock);
+	mutex_unlock(&desc->lock);
 	usb_autopm_put_interface(desc->intf);
 out:
 	mutex_unlock(&wdm_mutex);
@@ -556,9 +563,9 @@ 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);
+	mutex_lock(&desc->lock);
 	desc->count--;
-	mutex_unlock(&desc->plock);
+	mutex_unlock(&desc->lock);
 
 	if (!desc->count) {
 		dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
@@ -655,9 +662,7 @@ next_desc:
 	desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 	if (!desc)
 		goto out;
-	mutex_init(&desc->wlock);
-	mutex_init(&desc->rlock);
-	mutex_init(&desc->plock);
+	mutex_init(&desc->lock);
 	spin_lock_init(&desc->iuspin);
 	init_waitqueue_head(&desc->wait);
 	desc->wMaxCommand = maxcom;
@@ -771,14 +776,17 @@ static void wdm_disconnect(struct usb_interface *intf)
 	/* to terminate pending flushes */
 	clear_bit(WDM_IN_USE, &desc->flags);
 	spin_unlock_irqrestore(&desc->iuspin, flags);
-	cancel_work_sync(&desc->rxwork);
+	mutex_lock(&desc->lock);
 	kill_urbs(desc);
+	cancel_work_sync(&desc->rxwork);
+	mutex_unlock(&desc->lock);
 	wake_up_all(&desc->wait);
 	if (!desc->count)
 		cleanup(desc);
 	mutex_unlock(&wdm_mutex);
 }
 
+#ifdef CONFIG_PM
 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 {
 	struct wdm_device *desc = usb_get_intfdata(intf);
@@ -786,22 +794,30 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 
 	dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 
-	mutex_lock(&desc->plock);
-#ifdef CONFIG_PM
+	/* if this is an autosuspend the caller does the locking */
+	if (!(message.event & PM_EVENT_AUTO))
+		mutex_lock(&desc->lock);
+	spin_lock_irq(&desc->iuspin);
+
 	if ((message.event & PM_EVENT_AUTO) &&
-			test_bit(WDM_IN_USE, &desc->flags)) {
+			(test_bit(WDM_IN_USE, &desc->flags)
+			|| test_bit(WDM_RESPONDING, &desc->flags))) {
+		spin_unlock_irq(&desc->iuspin);
 		rv = -EBUSY;
 	} else {
-#endif
-		cancel_work_sync(&desc->rxwork);
+
+		set_bit(WDM_SUSPENDING, &desc->flags);
+		spin_unlock_irq(&desc->iuspin);
+		/* callback submits work - order is essential */
 		kill_urbs(desc);
-#ifdef CONFIG_PM
+		cancel_work_sync(&desc->rxwork);
 	}
-#endif
-	mutex_unlock(&desc->plock);
+	if (!(message.event & PM_EVENT_AUTO))
+		mutex_unlock(&desc->lock);
 
 	return rv;
 }
+#endif
 
 static int recover_from_urb_loss(struct wdm_device *desc)
 {
@@ -815,23 +831,27 @@ static int recover_from_urb_loss(struct wdm_device *desc)
 	}
 	return rv;
 }
+
+#ifdef CONFIG_PM
 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);
+
+	clear_bit(WDM_SUSPENDING, &desc->flags);
 	rv = recover_from_urb_loss(desc);
-	mutex_unlock(&desc->plock);
+
 	return rv;
 }
+#endif
 
 static int wdm_pre_reset(struct usb_interface *intf)
 {
 	struct wdm_device *desc = usb_get_intfdata(intf);
 
-	mutex_lock(&desc->plock);
+	mutex_lock(&desc->lock);
 	return 0;
 }
 
@@ -841,7 +861,7 @@ static int wdm_post_reset(struct usb_interface *intf)
 	int rv;
 
 	rv = recover_from_urb_loss(desc);
-	mutex_unlock(&desc->plock);
+	mutex_unlock(&desc->lock);
 	return 0;
 }
 
@@ -849,9 +869,11 @@ static struct usb_driver wdm_driver = {
 	.name =		"cdc_wdm",
 	.probe =	wdm_probe,
 	.disconnect =	wdm_disconnect,
+#ifdef CONFIG_PM
 	.suspend =	wdm_suspend,
 	.resume =	wdm_resume,
 	.reset_resume =	wdm_resume,
+#endif
 	.pre_reset =	wdm_pre_reset,
 	.post_reset =	wdm_post_reset,
 	.id_table =	wdm_ids,