diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c
index 8a781e2..1900abb 100644
--- a/drivers/mmc/host/tmio_mmc.c
+++ b/drivers/mmc/host/tmio_mmc.c
@@ -90,7 +90,7 @@
 		return -EINVAL;
 
 	/* SD control register space size is 0x200, 0x400 for bus_shift=1 */
-	pdata->bus_shift = resource_size(res_ctl) >> 10;
+	pdata->bus_shift = resource_size(res) >> 10;
 	pdata->flags |= TMIO_MMC_HAVE_HIGH_REG;
 
 	ret = tmio_mmc_host_probe(&host, pdev, pdata);