diff --git a/drivers/usb/gadget/at91_udc.c b/drivers/usb/gadget/at91_udc.c
index 043e04db2a0555e7548782d8ddeb967a31772bd7..12ac9cd32a07562ec665f04636b75a263f68d9a8 100644
--- a/drivers/usb/gadget/at91_udc.c
+++ b/drivers/usb/gadget/at91_udc.c
@@ -1656,9 +1656,7 @@ static int __init at91udc_probe(struct platform_device *pdev)
 	if (!res)
 		return -ENXIO;
 
-	if (!request_mem_region(res->start,
-			res->end - res->start + 1,
-			driver_name)) {
+	if (!request_mem_region(res->start, resource_size(res), driver_name)) {
 		DBG("someone's using UDC memory\n");
 		return -EBUSY;
 	}
@@ -1699,7 +1697,7 @@ static int __init at91udc_probe(struct platform_device *pdev)
 		udc->ep[3].maxpacket = 64;
 	}
 
-	udc->udp_baseaddr = ioremap(res->start, res->end - res->start + 1);
+	udc->udp_baseaddr = ioremap(res->start, resource_size(res));
 	if (!udc->udp_baseaddr) {
 		retval = -ENOMEM;
 		goto fail0a;
@@ -1781,7 +1779,7 @@ static int __init at91udc_probe(struct platform_device *pdev)
 	if (cpu_is_at91rm9200())
 		gpio_free(udc->board.pullup_pin);
 fail0:
-	release_mem_region(res->start, res->end - res->start + 1);
+	release_mem_region(res->start, resource_size(res));
 	DBG("%s probe failed, %d\n", driver_name, retval);
 	return retval;
 }
@@ -1813,7 +1811,7 @@ static int __exit at91udc_remove(struct platform_device *pdev)
 		gpio_free(udc->board.pullup_pin);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	release_mem_region(res->start, res->end - res->start + 1);
+	release_mem_region(res->start, resource_size(res));
 
 	clk_put(udc->iclk);
 	clk_put(udc->fclk);