diff --git a/target/linux/ramips/files-4.14/drivers/net/ethernet/mtk/gsw_mt7620.c b/target/linux/ramips/files-4.14/drivers/net/ethernet/mtk/gsw_mt7620.c
index b675ad0c4a..4093f09d41 100644
--- a/target/linux/ramips/files-4.14/drivers/net/ethernet/mtk/gsw_mt7620.c
+++ b/target/linux/ramips/files-4.14/drivers/net/ethernet/mtk/gsw_mt7620.c
@@ -166,6 +166,7 @@ static void mt7620_hw_init(struct mt7620_gsw *gsw, struct device_node *np)
 		_mt7620_mii_write(gsw, 4, 30, 0xa000);
 		_mt7620_mii_write(gsw, 4, 4, 0x05e1);
 		_mt7620_mii_write(gsw, 4, 16, 0x1313);
+		_mt7620_mii_write(gsw, 4, 0, 0x3100);
 		pr_info("gsw: setting port4 to ephy mode\n");
 	}
 }
diff --git a/target/linux/ramips/files-4.9/drivers/net/ethernet/mtk/gsw_mt7620.c b/target/linux/ramips/files-4.9/drivers/net/ethernet/mtk/gsw_mt7620.c
index b675ad0c4a..4093f09d41 100644
--- a/target/linux/ramips/files-4.9/drivers/net/ethernet/mtk/gsw_mt7620.c
+++ b/target/linux/ramips/files-4.9/drivers/net/ethernet/mtk/gsw_mt7620.c
@@ -166,6 +166,7 @@ static void mt7620_hw_init(struct mt7620_gsw *gsw, struct device_node *np)
 		_mt7620_mii_write(gsw, 4, 30, 0xa000);
 		_mt7620_mii_write(gsw, 4, 4, 0x05e1);
 		_mt7620_mii_write(gsw, 4, 16, 0x1313);
+		_mt7620_mii_write(gsw, 4, 0, 0x3100);
 		pr_info("gsw: setting port4 to ephy mode\n");
 	}
 }