samples/vfio-mdev/mtty: expand minor range when registering chrdev region

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@gmx.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 19cd29071ab0d9c7782ffd3d6066b98d18deaf1a..1c77c370c92f6a287ff211a04f3dcf00f2a590f0 100644 (file)
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -1442,7 +1442,8 @@ static int __init mtty_dev_init(void)
 
        idr_init(&mtty_dev.vd_idr);
 
-       ret = alloc_chrdev_region(&mtty_dev.vd_devt, 0, MINORMASK, MTTY_NAME);
+       ret = alloc_chrdev_region(&mtty_dev.vd_devt, 0, MINORMASK + 1,
+                                 MTTY_NAME);
 
        if (ret < 0) {
                pr_err("Error: failed to register mtty_dev, err:%d\n", ret);
@@ -1450,7 +1451,7 @@ static int __init mtty_dev_init(void)
        }
 
        cdev_init(&mtty_dev.vd_cdev, &vd_fops);
-       cdev_add(&mtty_dev.vd_cdev, mtty_dev.vd_devt, MINORMASK);
+       cdev_add(&mtty_dev.vd_cdev, mtty_dev.vd_devt, MINORMASK + 1);
 
        pr_info("major_number:%d\n", MAJOR(mtty_dev.vd_devt));
 
@@ -1487,7 +1488,7 @@ failed2:
 
 failed1:
        cdev_del(&mtty_dev.vd_cdev);
-       unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK);
+       unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
 
 all_done:
        return ret;
@@ -1501,7 +1502,7 @@ static void __exit mtty_dev_exit(void)
        device_unregister(&mtty_dev.dev);
        idr_destroy(&mtty_dev.vd_idr);
        cdev_del(&mtty_dev.vd_cdev);
-       unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK);
+       unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
        class_destroy(mtty_dev.vd_class);
        mtty_dev.vd_class = NULL;
        pr_info("mtty_dev: Unloaded!\n");