Re: [RFC] early init and DT platform devices allocation/registration

[Sebastian Hesselbarth <sebastian.hesselbarth-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On 06/26/13 12:03, Grant Likely wrote:
> On Wed, Jun 26, 2013 at 7:00 AM, Hiroshi Doyu <hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> wrote:
>> Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org> wrote @ Tue, 25 Jun 2013 19:52:33 +0200:
>>
>>>> Here's my workaround. I need to call of_detach_node() with OF_DYNAMIC
>>>> to avoid duplicated device registration.
>>>
>>> Gah! my eyes!
>>>
>>> Don't do that. It is incredibly problematic. Look at inhibiting
>>> duplicate device creation instead.
>>
>> I may not follow this thread correctly, but could anyone point out the
>> above "inhibiting duplicate device creation" if there's already such
>> solution?
>
> No, the solution doesn't exist yet, but it wouldn't be hard to
> implement. What you need to do is to add a struct device pointer to
> struct device_node, and set the pointer to the struct device when
> of_platform_device_create creates a device. (it would also need to be
> set for early_platform_device creation, but that's not something that
> should affect you). You would also add a check to
> of_platform_device_create to check if the device pointer is already
> set. If it is, then skip creation of the device.

Grant,

What about the other way round, i.e. check if there is a device with
.of_node pointed to the struct device_node currently at
of_platform_device_create?

That will avoid adding struct device to struct device_node which you
fought against for good reasons.

Also, I guess of_platform_device_create could be exported and used
by anyone who wants to create platform_devices early.

Sebastian