usb: dwc3: gadget: assign resource_index inside get_transfer_index()

Instead of returning resource index number just to assign it to a
field inside 'dep' which was passed as argument, we can assing
dep->resource_index from inside dwc3_gadget_ep_get_transfer_index()
itself.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/ep0.c

@@ -79,7 +79,7 @@ static int dwc3_ep0_start_trans(struct dwc3_ep *dep)
 	if (ret < 0)
 		return ret;
 
-	dep->resource_index = dwc3_gadget_ep_get_transfer_index(dep);
+	dwc3_gadget_ep_get_transfer_index(dep);
 	dwc->ep0_next_event = DWC3_EP0_COMPLETE;
 
 	return 0;

drivers/usb/dwc3/gadget.c

@@ -683,8 +683,7 @@ static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep, unsigned int action)
 		if (ret < 0)
 			return ret;
 
-		dep->resource_index = dwc3_gadget_ep_get_transfer_index(dep);
-		WARN_ON_ONCE(!dep->resource_index);
+		dwc3_gadget_ep_get_transfer_index(dep);
 	}
 
 out:
@@ -1245,10 +1244,8 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
 		return ret;
 	}
 
-	if (starting) {
-		dep->resource_index = dwc3_gadget_ep_get_transfer_index(dep);
-		WARN_ON_ONCE(!dep->resource_index);
-	}
+	if (starting)
+		dwc3_gadget_ep_get_transfer_index(dep);
 
 	return 0;
 }

drivers/usb/dwc3/gadget.h

@@ -98,13 +98,12 @@ int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol);
  * Caller should take care of locking. Returns the transfer resource
  * index for a given endpoint.
  */
-static inline u32 dwc3_gadget_ep_get_transfer_index(struct dwc3_ep *dep)
+static inline void dwc3_gadget_ep_get_transfer_index(struct dwc3_ep *dep)
 {
 	u32			res_id;
 
 	res_id = dwc3_readl(dep->regs, DWC3_DEPCMD);
-
-	return DWC3_DEPCMD_GET_RSC_IDX(res_id);
+	dep->resource_index = DWC3_DEPCMD_GET_RSC_IDX(res_id);
 }
 
 #endif /* __DRIVERS_USB_DWC3_GADGET_H */