diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
index db288fbd5a4d..c722ff2dc1fc 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
@@ -320,6 +320,9 @@ static int imx_dwmac_probe(struct platform_device *pdev)
 	if (data->flags & STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY)
 		plat_dat->flags |= STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY;
 
+	if (data->flags & STMMAC_FLAG_KEEP_PREAMBLE_BEFORE_SFD)
+		plat_dat->flags |= STMMAC_FLAG_KEEP_PREAMBLE_BEFORE_SFD;
+
 	/* Default TX Q0 to use TSO and rest TXQ for TBS */
 	for (int i = 1; i < plat_dat->tx_queues_to_use; i++)
 		plat_dat->tx_queues_cfg[i].tbs_en = 1;
@@ -355,7 +358,8 @@ static struct imx_dwmac_ops imx8mp_dwmac_data = {
 	.addr_width = 34,
 	.mac_rgmii_txclk_auto_adj = false,
 	.set_intf_mode = imx8mp_set_intf_mode,
-	.flags = STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY,
+	.flags = STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY |
+		 STMMAC_FLAG_KEEP_PREAMBLE_BEFORE_SFD,
 };
 
 static struct imx_dwmac_ops imx8dxl_dwmac_data = {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c2589f02ff7e..59e5fb2e7e05 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1206,6 +1206,7 @@ static int stmmac_init_phy(struct net_device *dev)
 	struct fwnode_handle *phy_fwnode;
 	struct fwnode_handle *fwnode;
 	struct ethtool_keee eee;
+	u32 dev_flags = 0;
 	int ret;
 
 	if (!phylink_expects_phy(priv->phylink))
@@ -1224,6 +1225,9 @@ static int stmmac_init_phy(struct net_device *dev)
 	else
 		phy_fwnode = NULL;
 
+	if (priv->plat->flags & STMMAC_FLAG_KEEP_PREAMBLE_BEFORE_SFD)
+		dev_flags |= PHY_F_KEEP_PREAMBLE_BEFORE_SFD;
+
 	/* Some DT bindings do not set-up the PHY handle. Let's try to
 	 * manually parse it
 	 */
@@ -1242,10 +1246,12 @@ static int stmmac_init_phy(struct net_device *dev)
 			return -ENODEV;
 		}
 
+		phydev->dev_flags |= dev_flags;
+
 		ret = phylink_connect_phy(priv->phylink, phydev);
 	} else {
 		fwnode_handle_put(phy_fwnode);
-		ret = phylink_fwnode_phy_connect(priv->phylink, fwnode, 0);
+		ret = phylink_fwnode_phy_connect(priv->phylink, fwnode, dev_flags);
 	}
 
 	if (ret) {
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 225d4adf28be..b2a584b60bff 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -101,6 +101,14 @@
 #define LAN8814_CABLE_DIAG_VCT_DATA_MASK	GENMASK(7, 0)
 #define LAN8814_PAIR_BIT_SHIFT			12
 
+/* KSZ9x31 remote loopback register */
+#define KSZ9x31_REMOTE_LOOPBACK			0x11
+/* This is an undocumented bit of the KSZ9131RNX.
+ * It was reported by NXP in cooperation with Micrel.
+ */
+#define KSZ9x31_REMOTE_LOOPBACK_KEEP_PREAMBLE	BIT(2)
+#define KSZ9x31_REMOTE_LOOPBACK_EN		BIT(8)
+
 #define LAN8814_SKUS				0xB
 
 #define LAN8814_WIRE_PAIR_MASK			0xF
@@ -1500,7 +1508,11 @@ static int ksz9131_config_init(struct phy_device *phydev)
 	if (ret < 0)
 		return ret;
 
-	return 0;
+	if (phydev->dev_flags & PHY_F_KEEP_PREAMBLE_BEFORE_SFD)
+		ret = phy_modify(phydev, KSZ9x31_REMOTE_LOOPBACK, 0,
+				 KSZ9x31_REMOTE_LOOPBACK_KEEP_PREAMBLE);
+
+	return ret;
 }
 
 #define MII_KSZ9131_AUTO_MDIX		0x1C
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 5972f19af16d..6f9979a26892 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -810,8 +810,9 @@ struct phy_device {
 };
 
 /* Generic phy_device::dev_flags */
-#define PHY_F_NO_IRQ		0x80000000
-#define PHY_F_RXC_ALWAYS_ON	0x40000000
+#define PHY_F_NO_IRQ			0x80000000
+#define PHY_F_RXC_ALWAYS_ON		0x40000000
+#define PHY_F_KEEP_PREAMBLE_BEFORE_SFD	0x20000000
 
 #define to_phy_device(__dev)	container_of_const(to_mdio_device(__dev), struct phy_device, mdio)
 
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index f1054b9c2d8a..e308c98c7bd3 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -191,6 +191,7 @@ enum dwmac_core_type {
 #define STMMAC_FLAG_EN_TX_LPI_CLOCKGATING	BIT(11)
 #define STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP	BIT(12)
 #define STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY	BIT(13)
+#define STMMAC_FLAG_KEEP_PREAMBLE_BEFORE_SFD	BIT(14)
 
 struct mac_device_info;