diff --git a/drivers/uwb/whc-rc.c b/drivers/uwb/whc-rc.c
index 70a004a..3ae3c70 100644
--- a/drivers/uwb/whc-rc.c
+++ b/drivers/uwb/whc-rc.c
@@ -222,7 +222,7 @@
 	struct umc_dev *umc_dev = whcrc->umc_dev;
 
 	whcrc->area = umc_dev->resource.start;
-	whcrc->rc_len = umc_dev->resource.end - umc_dev->resource.start + 1;
+	whcrc->rc_len = resource_size(&umc_dev->resource);
 	result = -EBUSY;
 	if (request_mem_region(whcrc->area, whcrc->rc_len, KBUILD_MODNAME) == NULL) {
 		dev_err(dev, "can't request URC region (%zu bytes @ 0x%lx): %d\n",