RE: [PATCH v8 08/14] usb: otg: add OTG/dual-role core

[Jun Li]

Hi Roger

> >>
> >> Here, we should be checking if user needs to disable any OTG
> >> features. So,
> >>
> >> 	if (dev->of_node)
> >> 		of_usb_update_otg_caps(dev->of_node, &otg->caps);
> >>
> >> Do you agree?
> >> This means we need to change otg->caps from 'struct usb_otg_caps
> *caps;'
> >> to 'struct usb_otg_caps caps;' so that we can modify the local copy
> >> instead of the one passed by the OTG controller.
> >
> > Why can't modify the one from OTG controller directly?
> >
> 
> There are 2 things.
> 1) OTG features supported by hardware. This is the controller's config-
> >otg_caps
> 2) OTG features needed by system designer. This can be a subset of (1).

Let's make things simple, we only need this subnet, which can be set
by controller driver in config->otg_caps before pass (its address)
to OTG core.

So controller driver should get the capability of HW(+SW) and user config
by whatever approach, then set its config->otg_caps.

Li Jun