diff --git a/target/linux/ramips/files-4.14/drivers/net/ethernet/mediatek/gsw_mt7620.c b/target/linux/ramips/files-4.14/drivers/net/ethernet/mediatek/gsw_mt7620.c
index 192603a68c..b1f1794bc9 100644
--- a/target/linux/ramips/files-4.14/drivers/net/ethernet/mediatek/gsw_mt7620.c
+++ b/target/linux/ramips/files-4.14/drivers/net/ethernet/mediatek/gsw_mt7620.c
@@ -189,6 +189,12 @@ static void mt7620_hw_init(struct mt7620_gsw *gsw, int mdio_mode)
 		_mt7620_mii_write(gsw, 4, 16, 0x1313);
 		_mt7620_mii_write(gsw, 4, 0, 0x3100);
 		pr_info("gsw: setting port4 to ephy mode\n");
+	} else if (!mdio_mode) {
+		u32 val = rt_sysc_r32(SYSC_REG_CFG1);
+
+		val &= ~(3 << 14);
+		rt_sysc_w32(val, SYSC_REG_CFG1);
+		pr_info("gsw: setting port4 to gmac mode\n");
 	}
 }