Re: [PATCH 01/14] chardev: add helper function to register char devs with a struct device

Logan Gunthorpe
2017-02-21T23:41:01Z

Hey,

Ok, I'll do a v2 later this week with some of the feedback and tags?

Logan

On 21/02/17 11:18 AM, Dan Williams wrote:
> On Mon, Feb 20, 2017 at 10:35 PM, Logan Gunthorpe <logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org> wrote:
>>
>>
>> On 20/02/17 10:35 PM, Dmitry Torokhov wrote:
>>> My only objection is to this statement. There is absolutely nothing that
>>> prevents from calling device_unregister() first and cdev_del() later.
>>> Refcounting will sort it all out.
>>
>> Yeah, I was really trying to warn people against calling cdev_del within
>> the release function of the device. If you do that, then the cdev
>> reference will block the device from ever getting released.
>>
>> Certainly, you could call device_unregister followed by cdev_del. I
>> could reword this if you feel it necessary.
>
> I agree with Dmitry, just delete the statement in parenthesis and the
> rest is fine. If you're modifying this patch it might be good to take
> the opportunity to add a WARN_ON(!parent->kobj.state_initialized) to
> catch attempts to call device_add_cdev() with an uninitialized device.
>
> You can also add:
>
> Signed-off-by: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>