From mboxrd@z Thu Jan  1 00:00:00 1970
From: john@jjdev.com (John de la Garza)
Date: Tue, 26 Aug 2014 20:48:41 -0400
Subject: cdev_init and struct file_operations
Message-ID: <20140827004839.GA4431@vega.jjdev.com>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

In the book Linux Device Drivers a struct cdev is setup like this:

static void scull_setup_cdev(struct scull_dev *dev, int index)
{
    int err, devno = MKDEV(scull_major, scull_minor + index);
    
    cdev_init(&dev->cdev, &scull_fops);
    dev->cdev.owner = THIS_MODULE;
    dev->cdev.ops = &scull_fops;
...


the code for cdev_init does this:
void cdev_init(struct cdev *cdev, const struct file_operations *fops)
{
        memset(cdev, 0, sizeof *cdev);
        INIT_LIST_HEAD(&cdev->list);
        kobject_init(&cdev->kobj, &ktype_cdev_default);
        cdev->ops = fops;
}

Why does the code from ldd3 set dev->cdev.ops = &scull_fops again?

Doesn't cdev_init already do that?