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> --- samples/vfio-mdev/mdpy.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c index 96e7969c473a..cc86bf6566e4 100644 --- a/samples/vfio-mdev/mdpy.c +++ b/samples/vfio-mdev/mdpy.c @@ -752,13 +752,13 @@ static int __init mdpy_dev_init(void) { int ret = 0; - ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK, MDPY_NAME); + ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME); if (ret < 0) { pr_err("Error: failed to register mdpy_dev, err: %d\n", ret); return ret; } cdev_init(&mdpy_cdev, &vd_fops); - cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK); + cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1); pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt)); mdpy_class = class_create(THIS_MODULE, MDPY_CLASS_NAME); @@ -787,7 +787,7 @@ static int __init mdpy_dev_init(void) class_destroy(mdpy_class); failed1: cdev_del(&mdpy_cdev); - unregister_chrdev_region(mdpy_devt, MINORMASK); + unregister_chrdev_region(mdpy_devt, MINORMASK + 1); return ret; } @@ -798,7 +798,7 @@ static void __exit mdpy_dev_exit(void) device_unregister(&mdpy_dev); cdev_del(&mdpy_cdev); - unregister_chrdev_region(mdpy_devt, MINORMASK); + unregister_chrdev_region(mdpy_devt, MINORMASK + 1); class_destroy(mdpy_class); mdpy_class = NULL; } -- 2.20.1