diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index 0a56d766978f..e761eb1b1441 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -477,7 +477,7 @@ static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot)
 	return ret;
 }
 
-int dw_mci_exynos_prepare_hs400_tuning(struct dw_mci *host,
+static int dw_mci_exynos_prepare_hs400_tuning(struct dw_mci *host,
 					struct mmc_ios *ios)
 {
 	struct dw_mci_exynos_priv_data *priv = host->priv;
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index b46b825aaeb5..47dfd0eafb7a 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1365,7 +1365,7 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	return err;
 }
 
-int dw_mci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios)
+static int dw_mci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios)
 {
 	struct dw_mci_slot *slot = mmc_priv(mmc);
 	struct dw_mci *host = slot->host;