4 files changed, 32 insertions, 33 deletions

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index a7e64af..81695d4 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1836,8 +1836,8 @@ static int uvc_probe(struct usb_interface *intf,
 	INIT_LIST_HEAD(&dev->chains);
 	INIT_LIST_HEAD(&dev->streams);
 	atomic_set(&dev->nstreams, 0);
-	atomic_set(&dev->users, 0);
 	atomic_set(&dev->nmappings, 0);
+	mutex_init(&dev->lock);
 
 	dev->udev = usb_get_dev(udev);
 	dev->intf = usb_get_intf(intf);
@@ -1950,8 +1950,13 @@ static int uvc_suspend(struct usb_interface *intf, pm_message_t message)
 
 	/* Controls are cached on the fly so they don't need to be saved. */
 	if (intf->cur_altsetting->desc.bInterfaceSubClass ==
-	    UVC_SC_VIDEOCONTROL)
-		return uvc_status_suspend(dev);
+	    UVC_SC_VIDEOCONTROL) {
+		mutex_lock(&dev->lock);
+		if (dev->users)
+			uvc_status_stop(dev);
+		mutex_unlock(&dev->lock);
+		return 0;
+	}
 
 	list_for_each_entry(stream, &dev->streams, list) {
 		if (stream->intf == intf)
@@ -1973,14 +1978,20 @@ static int __uvc_resume(struct usb_interface *intf, int reset)
 
 	if (intf->cur_altsetting->desc.bInterfaceSubClass ==
 	    UVC_SC_VIDEOCONTROL) {
-		if (reset) {
-			int ret = uvc_ctrl_resume_device(dev);
+		int ret = 0;
 
+		if (reset) {
+			ret = uvc_ctrl_resume_device(dev);
 			if (ret < 0)
 				return ret;
 		}
 
-		return uvc_status_resume(dev);
+		mutex_lock(&dev->lock);
+		if (dev->users)
+			ret = uvc_status_start(dev, GFP_NOIO);
+		mutex_unlock(&dev->lock);
+
+		return ret;
 	}
 
 	list_for_each_entry(stream, &dev->streams, list) {
diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
index b749277..f552ab9 100644
--- a/drivers/media/usb/uvc/uvc_status.c
+++ b/drivers/media/usb/uvc/uvc_status.c
@@ -206,32 +206,15 @@ void uvc_status_cleanup(struct uvc_device *dev)
 	uvc_input_cleanup(dev);
 }
 
-int uvc_status_start(struct uvc_device *dev)
+int uvc_status_start(struct uvc_device *dev, gfp_t flags)
 {
 	if (dev->int_urb == NULL)
 		return 0;
 
-	return usb_submit_urb(dev->int_urb, GFP_KERNEL);
+	return usb_submit_urb(dev->int_urb, flags);
 }
 
 void uvc_status_stop(struct uvc_device *dev)
 {
 	usb_kill_urb(dev->int_urb);
 }
-
-int uvc_status_suspend(struct uvc_device *dev)
-{
-	if (atomic_read(&dev->users))
-		usb_kill_urb(dev->int_urb);
-
-	return 0;
-}
-
-int uvc_status_resume(struct uvc_device *dev)
-{
-	if (dev->int_urb == NULL || atomic_read(&dev->users) == 0)
-		return 0;
-
-	return usb_submit_urb(dev->int_urb, GFP_NOIO);
-}
-
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index b2dc326..3afff92 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -498,16 +498,20 @@ static int uvc_v4l2_open(struct file *file)
 		return -ENOMEM;
 	}
 
-	if (atomic_inc_return(&stream->dev->users) == 1) {
-		ret = uvc_status_start(stream->dev);
+	mutex_lock(&stream->dev->lock);
+	if (stream->dev->users == 0) {
+		ret = uvc_status_start(stream->dev, GFP_KERNEL);
 		if (ret < 0) {
-			atomic_dec(&stream->dev->users);
+			mutex_unlock(&stream->dev->lock);
 			usb_autopm_put_interface(stream->dev->intf);
 			kfree(handle);
 			return ret;
 		}
 	}
 
+	stream->dev->users++;
+	mutex_unlock(&stream->dev->lock);
+
 	v4l2_fh_init(&handle->vfh, stream->vdev);
 	v4l2_fh_add(&handle->vfh);
 	handle->chain = stream->chain;
@@ -538,8 +542,10 @@ static int uvc_v4l2_release(struct file *file)
 	kfree(handle);
 	file->private_data = NULL;
 
-	if (atomic_dec_return(&stream->dev->users) == 0)
+	mutex_lock(&stream->dev->lock);
+	if (--stream->dev->users == 0)
 		uvc_status_stop(stream->dev);
+	mutex_unlock(&stream->dev->lock);
 
 	usb_autopm_put_interface(stream->dev->intf);
 	return 0;
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index af505fd..9e35982 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -514,7 +514,8 @@ struct uvc_device {
 	char name[32];
 
 	enum uvc_device_state state;
-	atomic_t users;
+	struct mutex lock;		/* Protects users */
+	unsigned int users;
 	atomic_t nmappings;
 
 	/* Video control interface */
@@ -660,10 +661,8 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
 /* Status */
 extern int uvc_status_init(struct uvc_device *dev);
 extern void uvc_status_cleanup(struct uvc_device *dev);
-extern int uvc_status_start(struct uvc_device *dev);
+extern int uvc_status_start(struct uvc_device *dev, gfp_t flags);
 extern void uvc_status_stop(struct uvc_device *dev);
-extern int uvc_status_suspend(struct uvc_device *dev);
-extern int uvc_status_resume(struct uvc_device *dev);
 
 /* Controls */
 extern const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops;