usb: dwc3: gadget: start transfer on XFER_COMPLETE

if by the time we get to XFER_COMPLETE we have
pending requests to be processed, instead of waiting
for a following XFER_NOT_READY, let's start the request
right away and, maybe, save the time of a few NAKs
due to lack of started transfers.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/gadget.c

@@ -1967,6 +1967,14 @@ static void dwc3_endpoint_transfer_complete(struct dwc3 *dwc,
 
 		dwc->u1u2 = 0;
 	}
+
+	if (is_xfer_complete && !usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
+		int ret;
+
+		ret = __dwc3_gadget_kick_transfer(dep, 0, 1);
+		if (!ret || ret == -EBUSY)
+			return;
+	}
 }
 
 static void dwc3_endpoint_interrupt(struct dwc3 *dwc,