Re: [linux-pm] [RFC/RFT][PATCH -mm 2/5] swsusp: userland interface (rev. 2)

Pavel Machek
2006-01-05T00:21:34Z

Hi!

> > +static int __init snapshot_dev_init(void)
> > +{
> > + int error;
> > +
> > + error = alloc_chrdev_region(&interface.devno, 0, 1, interface.name);
> > + if (error)
> > + return error;
> > + cdev_init(&interface.cdev, &snapshot_fops);
> > + interface.cdev.ops = &snapshot_fops;
> > + error = cdev_add(&interface.cdev, interface.devno, 1);
> > + if (error)
> > + goto Unregister;
> > + error = sysfs_create_file(&power_subsys.kset.kobj, &snapshot_attr.attr);
>
> Heh, that's a neat hack, register a sysfs file that contains the
> major:minor (there is a function that will print that the correct way,
> if you really want to do that), in sysfs. It's better to just register
> a misc character device with the name "snapshot", and then udev will
> create your userspace node with the proper major:minor all automatically
> for you.
>
> Unless you want to turn these into syscalls :)

Well, I think we simply want to get static major/minor allocated for
this device. It really uses read/write, IIRC, so no, I do not think we
want to make it a syscall.
Pavel

--
Thanks, Sharp!