Re: driver model, duplicate names question

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jul 16, 2013 at 09:34:57AM -0700, Srinivas Pandruvada wrote:
> Hi Greg,
> 
> I would like to create tree like structure using device model (struct 
> device, device_register/device_unregister) using parent/child 
> relationship while creation. I want to be able to create duplicate 
> names, when their parents are different, similar to a directory structure.
> I see that I can't create devices with duplicate names (device names), 
> even when their parents are different.

We actually check that?  Nice, I didn't realize that :)

> How can I allow duplicate names when their parents are different devices?
> I want to avoid flat model as I have parent child relationship and there 
> will be too many devices using flat model.

Devices on the same bus shouldn't have the same name, but if they are in
a "tree", it should be ok.  What check is erroring out?

> Why, I need?
> I am going to publish RFC for a new power cap class driver. We have a 
> multiple controllers under power cap class (they are devices). Under 
> which there are multiple power zones, with parent/child relationships. 
> Currently I have to use  kobject_init_and_add, which I want to avoid and 
> just use device_register. Other places, wherever such relationships are 
> required, kobjects are used like cpufreq.

Yes, you shouldn't use "raw" kobject calls at all, so we should fix
this.

thanks,

greg k-h