diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
index 87c1b7c34c0e82bc0684f1fcb8bd28e7f917c225..51bd0edf544fc56b9463ea130711bd4e9767d9b6 100644
--- a/drivers/usb/host/ehci-atmel.c
+++ b/drivers/usb/host/ehci-atmel.c
@@ -149,7 +149,7 @@ static int __init ehci_atmel_drv_probe(struct platform_device *pdev)
 		goto fail_request_resource;
 	}
 	hcd->rsrc_start = res->start;
-	hcd->rsrc_len = res->end - res->start + 1;
+	hcd->rsrc_len = resource_size(res);
 
 	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
 				driver->description)) {