usb: dwc3: gadget: interrupt on ring full too

If the ring is full and we are processing a big
sglist, then let's interrupt so we can, later, add
more TRBs to the ring.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/gadget.c

@@ -758,6 +758,8 @@ static void dwc3_gadget_ep_free_request(struct usb_ep *ep,
 	kfree(req);
 }
 
+static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep);
+
 /**
  * dwc3_prepare_one_trb - setup one TRB from one request
  * @dep: endpoint for which this request is prepared
@@ -818,7 +820,8 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
 	/* always enable Continue on Short Packet */
 	trb->ctrl |= DWC3_TRB_CTRL_CSP;
 
-	if (!req->request.no_interrupt && !chain)
+	if ((!req->request.no_interrupt && !chain) ||
+			(dwc3_calc_trbs_left(dep) == 0))
 		trb->ctrl |= DWC3_TRB_CTRL_IOC | DWC3_TRB_CTRL_ISP_IMI;
 
 	if (chain)