cdev_init and struct file_operations
John de la Garza
john at jjdev.com
Tue Aug 26 20:48:41 EDT 2014
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?
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