diff --git a/drivers/usb/mtu3/mtu3_core.c b/drivers/usb/mtu3/mtu3_core.c
index 520e55a760c97a24bdea607da53ac34f947ec4bd..603b7f84d31e494a1a6e9c9542086d8d64e98d43 100644
--- a/drivers/usb/mtu3/mtu3_core.c
+++ b/drivers/usb/mtu3/mtu3_core.c
@@ -696,7 +696,7 @@ static irqreturn_t mtu3_u2_common_isr(struct mtu3 *mtu)
 	return IRQ_HANDLED;
 }
 
-irqreturn_t mtu3_irq(int irq, void *data)
+static irqreturn_t mtu3_irq(int irq, void *data)
 {
 	struct mtu3 *mtu = (struct mtu3 *)data;
 	unsigned long flags;
diff --git a/drivers/usb/mtu3/mtu3_qmu.c b/drivers/usb/mtu3/mtu3_qmu.c
index a6dd292c63ecc3003b6b7bb42578937641d0dede..7d9ba8a52368f6a4e3ed7b95fd6daa99f8fd9430 100644
--- a/drivers/usb/mtu3/mtu3_qmu.c
+++ b/drivers/usb/mtu3/mtu3_qmu.c
@@ -168,7 +168,7 @@ static struct qmu_gpd *advance_deq_gpd(struct mtu3_gpd_ring *ring)
 }
 
 /* check if a ring is emtpy */
-int gpd_ring_empty(struct mtu3_gpd_ring *ring)
+static int gpd_ring_empty(struct mtu3_gpd_ring *ring)
 {
 	struct qmu_gpd *enq = ring->enqueue;
 	struct qmu_gpd *next;