diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index 476fb4d..d4608c2 100644
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -129,7 +129,7 @@
 	if (!hcd)
 		return -ENOMEM;
 	hcd->rsrc_start = pdev->resource[0].start;
-	hcd->rsrc_len = pdev->resource[0].end - pdev->resource[0].start + 1;
+	hcd->rsrc_len = resource_size(&pdev->resource[0]);
 
 	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
 		pr_debug("request_mem_region failed\n");