Actually, total amount of available minor number for a single major is MINORMARK + 1. So expand minor range when registering chrdev region. Signed-off-by: Chengguang Xu <cgxu519@xxxxxxx> --- drivers/vfio/vfio.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 64833879f75d..a3030cdf3c18 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -2219,12 +2219,12 @@ static int __init vfio_init(void) vfio.class->devnode = vfio_devnode; - ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK, "vfio"); + ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); if (ret) goto err_alloc_chrdev; cdev_init(&vfio.group_cdev, &vfio_group_fops); - ret = cdev_add(&vfio.group_cdev, vfio.group_devt, MINORMASK); + ret = cdev_add(&vfio.group_cdev, vfio.group_devt, MINORMASK + 1); if (ret) goto err_cdev_add; @@ -2236,7 +2236,7 @@ static int __init vfio_init(void) return 0; err_cdev_add: - unregister_chrdev_region(vfio.group_devt, MINORMASK); + unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); err_alloc_chrdev: class_destroy(vfio.class); vfio.class = NULL; @@ -2254,7 +2254,7 @@ static void __exit vfio_cleanup(void) #endif idr_destroy(&vfio.group_idr); cdev_del(&vfio.group_cdev); - unregister_chrdev_region(vfio.group_devt, MINORMASK); + unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); class_destroy(vfio.class); vfio.class = NULL; misc_deregister(&vfio_dev); -- 2.20.1