Hi,

Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org> writes:
> [ Unknown signature status ]
> On 20/06/16 10:21, Felipe Balbi wrote:
>> 
>> Hi,
>> 
>> Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org> writes:
>>> The OTG core will use struct otg_gadget_ops to
>>> start/stop the gadget controller.
>>>
>>> The main purpose of this interface is to avoid directly
>>> calling usb_gadget_start/stop() from the OTG core as they
>>> wouldn't be defined in the built-in symbol table if
>>> CONFIG_USB_GADGET is m.
>>>
>>> Signed-off-by: Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org>
>>> ---
>>>  include/linux/usb/gadget.h | 16 ++++++++++++++++
>>>  1 file changed, 16 insertions(+)
>>>
>>> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
>>> index 2dd9e6b..f4fc0aa 100644
>>> --- a/include/linux/usb/gadget.h
>>> +++ b/include/linux/usb/gadget.h
>>> @@ -639,6 +639,22 @@ struct usb_gadget_driver {
>>>  };
>>>  
>>>  
>>> +/*-------------------------------------------------------------------------*/
>>> +
>>> +/**
>>> + * struct otg_gadget_ops - Interface between OTG core and gadget
>>> + *
>>> + * Provided by the gadget core to allow the OTG core to start/stop the gadget
>>> + *
>>> + * @start: function to start the gadget
>>> + * @stop: function to stop the gadget
>>> + * @connect_control: function to connect/disconnect from the bus
>>> + */
>>> +struct otg_gadget_ops {
>>> +	int (*start)(struct usb_gadget *gadget);
>>> +	int (*stop)(struct usb_gadget *gadget);
>>> +	int (*connect_control)(struct usb_gadget *gadget, bool connect);
>>> +};
>> 
>> you shouldn't need these at all. They are already part of the gadget
>> framework as ->udc_start(), ->udc_stop() and ->pullup()
>> 
>
> This is to avoid the undefined symbol errors during build when OTG has is
> built-in because USB (host) is built-in but GADGET is still a module.

change your Kconfig dependencies. OTG layer shouldn't be built-in unless
both Gadget and Host are built-in.

-- 
balbi