file->private_data = NULL;
int tpm_release(struct inode *inode, struct file *file){	struct tpm_chip *chip = file->private_data;		file->private_data = NULL;	spin_lock(&driver_lock);	chip->num_opens--;	del_singleshot_timer_sync(&chip->user_read_timer);	atomic_set(&chip->data_pending, 0);	pci_dev_put(chip->pci_dev);	return 0;}