unregister_chrdev_region
unregister_chrdev_region(IB_UCM_BASE_DEV, IB_UCM_MAX_DEVICES);
unregister_chrdev_region(IB_UCM_BASE_DEV, IB_UCM_MAX_DEVICES);
unregister_chrdev_region(overflow_maj, IB_UCM_MAX_DEVICES);
unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
unregister_chrdev_region(base_dev, IB_UMAD_MAX_PORTS * 2);
unregister_chrdev_region(overflow_maj, IB_UMAD_MAX_PORTS * 2);
unregister_chrdev_region(dynamic_uverbs_dev,
unregister_chrdev_region(IB_UVERBS_BASE_DEV,
unregister_chrdev_region(IB_UVERBS_BASE_DEV,
unregister_chrdev_region(dynamic_uverbs_dev,