diff options
Diffstat (limited to 'drivers/usb/misc/usblcd.c')
| -rw-r--r-- | drivers/usb/misc/usblcd.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/usb/misc/usblcd.c b/drivers/usb/misc/usblcd.c index ada2ebc464ae..887ef953f3d8 100644 --- a/drivers/usb/misc/usblcd.c +++ b/drivers/usb/misc/usblcd.c @@ -47,6 +47,7 @@ struct usb_lcd { #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) static struct usb_driver lcd_driver; +static DEFINE_MUTEX(usb_lcd_open_mutex); static void lcd_delete(struct kref *kref) @@ -68,6 +69,7 @@ static int lcd_open(struct inode *inode, struct file *file) subminor = iminor(inode); + mutex_lock(&usb_lcd_open_mutex); interface = usb_find_interface(&lcd_driver, subminor); if (!interface) { err ("USBLCD: %s - error, can't find device for minor %d", @@ -89,6 +91,7 @@ static int lcd_open(struct inode *inode, struct file *file) file->private_data = dev; exit: + mutex_unlock(&usb_lcd_open_mutex); return retval; } @@ -347,7 +350,7 @@ static void lcd_disconnect(struct usb_interface *interface) int minor = interface->minor; /* prevent skel_open() from racing skel_disconnect() */ - lock_kernel(); + mutex_lock(&usb_lcd_open_mutex); dev = usb_get_intfdata(interface); usb_set_intfdata(interface, NULL); @@ -355,7 +358,7 @@ static void lcd_disconnect(struct usb_interface *interface) /* give back our minor */ usb_deregister_dev(interface, &lcd_class); - unlock_kernel(); + mutex_unlock(&usb_lcd_open_mutex); /* decrement our usage count */ kref_put(&dev->kref, lcd_delete); |