Re: [PATCH 1/2] chrdev: implement __[un]register_chrdev()

From: Tejun Heo
Date: Wed Aug 05 2009 - 13:00:17 EST


Greg KH wrote:
> On Thu, Aug 06, 2009 at 01:30:30AM +0900, Tejun Heo wrote:
>> Greg KH wrote:
>>> On Wed, Aug 05, 2009 at 03:35:42PM +0900, Tejun Heo wrote:
>>>> [un]register_chrdev() assume minor range 0-255. This patch adds __
>>>> prefixed versions which take @minorbase and @count explicitly.
>>> What's the difference between this and the existing
>>> register_chrdev_region() function? Why doesn't that work for you?
>>>
>>> What am I missing here?
>> The function names in char_dev.c are quite confusing.
>
> That's an understatement :)

Yeah, it sure is. It should have used a different verb at the very
least.

>> register_chrdev_region() only registers chrdev region.
>> register_chrdev() registers chrdev region and creates a cdev for the
>> region. :-)
>
> Yes, but you can use register_chrdev_region() and then call cdev_alloc()
> for the specific cdevs you need, right? It's not the prettiest, but it
> should work.

Yeap, I can. That's basically what register_chrdev() is. If it had a
better name, adding a new variant would have been much nicer. Having
the helper makes sense tho. Names too confusing?

Thanks.

--
tejun
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