diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index 8b90da5a6ed19..5e003baabac91 100644
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -590,10 +590,12 @@ static u32 get_esit_boundary(struct mu3h_sch_ep_info *sch_ep)
 	u32 boundary = sch_ep->esit;
 
 	if (sch_ep->sch_tt) { /* LS/FS with TT */
-		/* tune for CS */
-		if (sch_ep->ep_type != ISOC_OUT_EP)
-			boundary++;
-		else if (boundary > 1) /* normally esit >= 8 for FS/LS */
+		/*
+		 * tune for CS, normally esit >= 8 for FS/LS,
+		 * not add one for other types to avoid access array
+		 * out of boundary
+		 */
+		if (sch_ep->ep_type == ISOC_OUT_EP && boundary > 1)
 			boundary--;
 	}