staging: comedi: use centralized error clean-up in comedi_init()

Centralize the "clean-up on error" handling in `comedi_init()` using
`goto` statements.  Also change some of the explicit `-EIO` return
values to the error return values from the failing functions as there is
no good reason to use `-EIO` explicitly.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 4ed485a..ca11be2 100644 (file)
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -2881,29 +2881,25 @@ static int __init comedi_init(void)
        retval = register_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
                                        COMEDI_NUM_MINORS, "comedi");
        if (retval)
-               return -EIO;
+               return retval;
+
        cdev_init(&comedi_cdev, &comedi_fops);
        comedi_cdev.owner = THIS_MODULE;
 
        retval = kobject_set_name(&comedi_cdev.kobj, "comedi");
-       if (retval) {
-               unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
-                                        COMEDI_NUM_MINORS);
-               return retval;
-       }
+       if (retval)
+               goto out_unregister_chrdev_region;
+
+       retval = cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0),
+                         COMEDI_NUM_MINORS);
+       if (retval)
+               goto out_unregister_chrdev_region;
 
-       if (cdev_add(&comedi_cdev, MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS)) {
-               unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
-                                        COMEDI_NUM_MINORS);
-               return -EIO;
-       }
        comedi_class = class_create(THIS_MODULE, "comedi");
        if (IS_ERR(comedi_class)) {
+               retval = PTR_ERR(comedi_class);
                pr_err("failed to create class\n");
-               cdev_del(&comedi_cdev);
-               unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
-                                        COMEDI_NUM_MINORS);
-               return PTR_ERR(comedi_class);
+               goto out_cdev_del;
        }
 
        comedi_class->dev_groups = comedi_dev_groups;
@@ -2914,12 +2910,8 @@ static int __init comedi_init(void)
 
                dev = comedi_alloc_board_minor(NULL);
                if (IS_ERR(dev)) {
-                       comedi_cleanup_board_minors();
-                       class_destroy(comedi_class);
-                       cdev_del(&comedi_cdev);
-                       unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0),
-                                                COMEDI_NUM_MINORS);
-                       return PTR_ERR(dev);
+                       retval = PTR_ERR(dev);
+                       goto out_cleanup_board_minors;
                }
                /* comedi_alloc_board_minor() locked the mutex */
                mutex_unlock(&dev->mutex);
@@ -2929,6 +2921,15 @@ static int __init comedi_init(void)
        comedi_proc_init();
 
        return 0;
+
+out_cleanup_board_minors:
+       comedi_cleanup_board_minors();
+       class_destroy(comedi_class);
+out_cdev_del:
+       cdev_del(&comedi_cdev);
+out_unregister_chrdev_region:
+       unregister_chrdev_region(MKDEV(COMEDI_MAJOR, 0), COMEDI_NUM_MINORS);
+       return retval;
 }
 module_init(comedi_init);