Re: [PATCH] usb: gadget: add claimed field in struct usb_ep

[Robert Baldyga <r.baldyga@samsung.com>]

On 06/23/2014 08:27 PM, Felipe Balbi wrote:
> Hi,
> 
> On Mon, Jun 23, 2014 at 08:07:43AM +0200, Robert Baldyga wrote:
>> On 06/19/2014 05:08 PM, Felipe Balbi wrote:
>>> On Mon, Jun 16, 2014 at 10:20:36AM +0200, Robert Baldyga wrote:
>>>> This field allows to mark ep as claimed in more clear way. Claiming
>>>> endpoint by setting driver_data to non-null value is leaky solution
>>>> and makes code unreadable.
>>>
>>> how come ? How can it be unreadable ? how can it be leaky ?
>>>
>>
>> What if gadget will not assign any value to driver_data (just like
>> Gadget Zero do)? Endpoint will be seen as not used, and autoconfig will
> 
> huh ??? The gadget isn't the endpoint user, the function is. Look at
> f_sourcesink.c and f_loopback.c. If the function doesn't set anything to
> driver_data, then that's a bug on the function which needs fixing.
> 
> Moreover, if there's a function which doesn't set driver_data, we could
> just as well have a function which doesn't set "claimed", so the problem
> is the same.
> 

I mean the function, not the gadget. Sorry for confusion.
Mechanism I developed marks endpoint as claimed *inside autoconfig
function*. It's significant difference, because there's not possible to
forget to mark that endpoint is claimed. When endpoint is returned from
autoconfig function, it belongs to function, and the function doesn't
need to do anything to claim obtained endpoint - it's already done.