Hi,

On Thu, Jul 18, 2013 at 09:50:37AM -0400, Alan Stern wrote:
> On Thu, 18 Jul 2013, Felipe Balbi wrote:
> 
> > > > yes. Only the UDC driver knows when the controller is moving among those
> > > > states.
> > > 
> > > Not quite.  Only the gadget driver knows when the transition between 
> > > ADDRESS and CONFIGURED occurs.  This should be added to composite.c.
> > 
> > that's not entirely true :-) See how we handle that in dwc3:
> > 
> > | static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest 
> > *ctrl)
> > | {
> > |   enum usb_device_state state = dwc->gadget.state;
> > |   u32 cfg;
> > |   int ret;
> > |   u32 reg;
> > | 
> > |   dwc->start_config_issued = false;
> > |   cfg = le16_to_cpu(ctrl->wValue);
> > | 
> > |   switch (state) {
> > |   case USB_STATE_DEFAULT:
> > |           return -EINVAL;
> > |           break;
> > | 
> > |   case USB_STATE_ADDRESS:
> > |           ret = dwc3_ep0_delegate_req(dwc, ctrl);
> > |           /* if the cfg matches and the cfg is non zero */
> > |           if (cfg && (!ret || (ret == USB_GADGET_DELAYED_STATUS))) {
> > |                   usb_gadget_set_state(&dwc->gadget,
> > |                                   USB_STATE_CONFIGURED);
> 
> In theory, this should not occur until the gadget driver has finished 
> the transition to the CONFIGURED state, which doesn't occur until later 
> in the case of USB_GADGET_DELAYED_STATUS.
> 
> > | 
> > |                   /*
> > |                    * Enable transition to U1/U2 state when
> > |                    * nothing is pending from application.
> > |                    */
> > |                   reg = dwc3_readl(dwc->regs, DWC3_DCTL);
> > |                   reg |= (DWC3_DCTL_ACCEPTU1ENA | DWC3_DCTL_ACCEPTU2ENA);
> > |                   dwc3_writel(dwc->regs, DWC3_DCTL, reg);
> > | 
> > |                   dwc->resize_fifos = true;
> > |                   dev_dbg(dwc->dev, "resize fifos flag SET\n");
> > |           }
> > |           break;
> > | 
> > |   case USB_STATE_CONFIGURED:
> > |           ret = dwc3_ep0_delegate_req(dwc, ctrl);
> > |           if (!cfg)
> > |                   usb_gadget_set_state(&dwc->gadget,
> > |                                   USB_STATE_ADDRESS);
> 
> No check on the value of ret?  What if the request was rejected?
> 
> > |           break;
> > |   default:
> > |           ret = -EINVAL;
> > |   }
> > |   return ret;
> > | }
> 
> This illustrates the folly of exposing your code to public review.  :-)

it's always good to have extra eyes looking at the code, I'll patch
those up, but since it has always been like that and nobody complained,
I won't tag it for stable.

-- 
balbi

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