1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c
index fbea8563df1e..9b53e8df4648 100644
--- a/drivers/usb/atm/usbatm.c
+++ b/drivers/usb/atm/usbatm.c
@@ -1333,6 +1333,7 @@ void usbatm_usb_disconnect(struct usb_interface *intf)
         if (instance->atm_dev) {
                 sysfs_remove_link(&instance->atm_dev->class_dev.kobj, "device");
                 atm_dev_deregister(instance->atm_dev);
+                instance->atm_dev = NULL;
         }
 
         usbatm_put_instance(instance);  /* taken in usbatm_usb_probe */
@@ -1348,7 +1349,7 @@ static int __init usbatm_usb_init(void)
 {
         dbg("%s: driver version %s", __func__, DRIVER_VERSION);
 
-        if (sizeof(struct usbatm_control) > sizeof(((struct sk_buff *) 0)->cb)) {
+        if (sizeof(struct usbatm_control) > FIELD_SIZEOF(struct sk_buff, cb)) {
                 printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
                 return -EIO;
         }