diff --git a/drivers/net/dsa/mt7530-mdio.c b/drivers/net/dsa/mt7530-mdio.c
index 088533663b83..fa3ee85a99c1 100644
--- a/drivers/net/dsa/mt7530-mdio.c
+++ b/drivers/net/dsa/mt7530-mdio.c
@@ -81,17 +81,14 @@ static const struct regmap_bus mt7530_regmap_bus = {
 };
 
 static int
-mt7531_create_sgmii(struct mt7530_priv *priv, bool dual_sgmii)
+mt7531_create_sgmii(struct mt7530_priv *priv)
 {
 	struct regmap_config *mt7531_pcs_config[2] = {};
 	struct phylink_pcs *pcs;
 	struct regmap *regmap;
 	int i, ret = 0;
 
-	/* MT7531AE has two SGMII units for port 5 and port 6
-	 * MT7531BE has only one SGMII unit for port 6
-	 */
-	for (i = dual_sgmii ? 0 : 1; i < 2; i++) {
+	for (i = priv->p5_sgmii ? 0 : 1; i < 2; i++) {
 		mt7531_pcs_config[i] = devm_kzalloc(priv->dev,
 						    sizeof(struct regmap_config),
 						    GFP_KERNEL);
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index cf2ff7680c15..68be38ae66e0 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -487,15 +487,6 @@ mt7530_pad_clk_setup(struct dsa_switch *ds, phy_interface_t interface)
 	return 0;
 }
 
-static bool mt7531_dual_sgmii_supported(struct mt7530_priv *priv)
-{
-	u32 val;
-
-	val = mt7530_read(priv, MT7531_TOP_SIG_SR);
-
-	return (val & PAD_DUAL_SGMII_EN) != 0;
-}
-
 static int
 mt7531_pad_setup(struct dsa_switch *ds, phy_interface_t interface)
 {
@@ -510,9 +501,6 @@ mt7531_pll_setup(struct mt7530_priv *priv)
 	u32 xtal;
 	u32 val;
 
-	if (mt7531_dual_sgmii_supported(priv))
-		return;
-
 	val = mt7530_read(priv, MT7531_CREV);
 	top_sig = mt7530_read(priv, MT7531_TOP_SIG_SR);
 	hwstrap = mt7530_read(priv, MT7531_HWTRAP);
@@ -920,8 +908,6 @@ static const char *p5_intf_modes(unsigned int p5_interface)
 		return "PHY P4";
 	case P5_INTF_SEL_GMAC5:
 		return "GMAC5";
-	case P5_INTF_SEL_GMAC5_SGMII:
-		return "GMAC5_SGMII";
 	default:
 		return "unknown";
 	}
@@ -956,9 +942,6 @@ static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface)
 		/* MT7530_P5_MODE_GMAC: P5 -> External phy or 2nd GMAC */
 		val &= ~MHWTRAP_P5_DIS;
 		break;
-	case P5_DISABLED:
-		interface = PHY_INTERFACE_MODE_NA;
-		break;
 	default:
 		dev_err(ds->dev, "Unsupported p5_intf_sel %d\n",
 			priv->p5_intf_sel);
@@ -992,8 +975,6 @@ static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface)
 	dev_dbg(ds->dev, "Setup P5, HWTRAP=0x%x, intf_sel=%s, phy-mode=%s\n",
 		val, p5_intf_modes(priv->p5_intf_sel), phy_modes(interface));
 
-	priv->p5_interface = interface;
-
 unlock_exit:
 	mutex_unlock(&priv->reg_mutex);
 }
@@ -1035,10 +1016,6 @@ mt753x_cpu_port_enable(struct dsa_switch *ds, int port)
 	mt7530_set(priv, MT7530_MFC, BC_FFP(BIT(port)) | UNM_FFP(BIT(port)) |
 		   UNU_FFP(BIT(port)));
 
-	/* Set CPU port number */
-	if (priv->id == ID_MT7530 || priv->id == ID_MT7621)
-		mt7530_rmw(priv, MT7530_MFC, CPU_MASK, CPU_EN | CPU_PORT(port));
-
 	/* Add the CPU port to the CPU port bitmap for MT7531 and the switch on
 	 * the MT7988 SoC. Trapped frames will be forwarded to the CPU port that
 	 * is affine to the inbound user port.
@@ -2344,16 +2321,13 @@ mt7530_setup(struct dsa_switch *ds)
 		return ret;
 
 	/* Setup port 5 */
-	priv->p5_intf_sel = P5_DISABLED;
-	interface = PHY_INTERFACE_MODE_NA;
-
 	if (!dsa_is_unused_port(ds, 5)) {
 		priv->p5_intf_sel = P5_INTF_SEL_GMAC5;
-		ret = of_get_phy_mode(dsa_to_port(ds, 5)->dn, &interface);
-		if (ret && ret != -ENODEV)
-			return ret;
 	} else {
-		/* Scan the ethernet nodes. look for GMAC1, lookup used phy */
+		/* Scan the ethernet nodes. Look for GMAC1, lookup the used PHY.
+		 * Set priv->p5_intf_sel to the appropriate value if PHY muxing
+		 * is detected.
+		 */
 		for_each_child_of_node(dn, mac_np) {
 			if (!of_device_is_compatible(mac_np,
 						     "mediatek,eth-mac"))
@@ -2384,6 +2358,10 @@ mt7530_setup(struct dsa_switch *ds)
 			of_node_put(phy_node);
 			break;
 		}
+
+		if (priv->p5_intf_sel == P5_INTF_SEL_PHY_P0 ||
+		    priv->p5_intf_sel == P5_INTF_SEL_PHY_P4)
+			mt7530_setup_port5(ds, interface);
 	}
 
 #ifdef CONFIG_GPIOLIB
@@ -2394,8 +2372,6 @@ mt7530_setup(struct dsa_switch *ds)
 	}
 #endif /* CONFIG_GPIOLIB */
 
-	mt7530_setup_port5(ds, interface);
-
 	/* Flush the FDB table */
 	ret = mt7530_fdb_cmd(priv, MT7530_FDB_FLUSH, NULL);
 	if (ret < 0)
@@ -2492,6 +2468,12 @@ mt7531_setup(struct dsa_switch *ds)
 		return -ENODEV;
 	}
 
+	/* MT7531AE has got two SGMII units. One for port 5, one for port 6.
+	 * MT7531BE has got only one SGMII unit which is for port 6.
+	 */
+	val = mt7530_read(priv, MT7531_TOP_SIG_SR);
+	priv->p5_sgmii = !!(val & PAD_DUAL_SGMII_EN);
+
 	/* all MACs must be forced link-down before sw reset */
 	for (i = 0; i < MT7530_NUM_PORTS; i++)
 		mt7530_write(priv, MT7530_PMCR_P(i), MT7531_FORCE_LNK);
@@ -2501,21 +2483,18 @@ mt7531_setup(struct dsa_switch *ds)
 		     SYS_CTRL_PHY_RST | SYS_CTRL_SW_RST |
 		     SYS_CTRL_REG_RST);
 
-	mt7531_pll_setup(priv);
-
-	if (mt7531_dual_sgmii_supported(priv)) {
-		priv->p5_intf_sel = P5_INTF_SEL_GMAC5_SGMII;
-
+	if (!priv->p5_sgmii) {
+		mt7531_pll_setup(priv);
+	} else {
 		/* Let ds->user_mii_bus be able to access external phy. */
 		mt7530_rmw(priv, MT7531_GPIO_MODE1, MT7531_GPIO11_RG_RXD2_MASK,
 			   MT7531_EXT_P_MDC_11);
 		mt7530_rmw(priv, MT7531_GPIO_MODE1, MT7531_GPIO12_RG_RXD3_MASK,
 			   MT7531_EXT_P_MDIO_12);
-	} else {
-		priv->p5_intf_sel = P5_INTF_SEL_GMAC5;
 	}
-	dev_dbg(ds->dev, "P5 support %s interface\n",
-		p5_intf_modes(priv->p5_intf_sel));
+
+	if (!dsa_is_unused_port(ds, 5))
+		priv->p5_intf_sel = P5_INTF_SEL_GMAC5;
 
 	mt7530_rmw(priv, MT7531_GPIO_MODE0, MT7531_GPIO0_MASK,
 		   MT7531_GPIO0_INTERRUPT);
@@ -2553,12 +2532,14 @@ static void mt7530_mac_port_get_caps(struct dsa_switch *ds, int port,
 				     struct phylink_config *config)
 {
 	switch (port) {
-	case 0 ... 4: /* Internal phy */
+	/* Ports which are connected to switch PHYs. There is no MII pinout. */
+	case 0 ... 4:
 		__set_bit(PHY_INTERFACE_MODE_GMII,
 			  config->supported_interfaces);
 		break;
 
-	case 5: /* 2nd cpu port with phy of port 0 or 4 / external phy */
+	/* Port 5 supports rgmii with delays, mii, and gmii. */
+	case 5:
 		phy_interface_set_rgmii(config->supported_interfaces);
 		__set_bit(PHY_INTERFACE_MODE_MII,
 			  config->supported_interfaces);
@@ -2566,7 +2547,8 @@ static void mt7530_mac_port_get_caps(struct dsa_switch *ds, int port,
 			  config->supported_interfaces);
 		break;
 
-	case 6: /* 1st cpu port */
+	/* Port 6 supports rgmii and trgmii. */
+	case 6:
 		__set_bit(PHY_INTERFACE_MODE_RGMII,
 			  config->supported_interfaces);
 		__set_bit(PHY_INTERFACE_MODE_TRGMII,
@@ -2575,30 +2557,30 @@ static void mt7530_mac_port_get_caps(struct dsa_switch *ds, int port,
 	}
 }
 
-static bool mt7531_is_rgmii_port(struct mt7530_priv *priv, u32 port)
-{
-	return (port == 5) && (priv->p5_intf_sel != P5_INTF_SEL_GMAC5_SGMII);
-}
-
 static void mt7531_mac_port_get_caps(struct dsa_switch *ds, int port,
 				     struct phylink_config *config)
 {
 	struct mt7530_priv *priv = ds->priv;
 
 	switch (port) {
-	case 0 ... 4: /* Internal phy */
+	/* Ports which are connected to switch PHYs. There is no MII pinout. */
+	case 0 ... 4:
 		__set_bit(PHY_INTERFACE_MODE_GMII,
 			  config->supported_interfaces);
 		break;
 
-	case 5: /* 2nd cpu port supports either rgmii or sgmii/8023z */
-		if (mt7531_is_rgmii_port(priv, port)) {
+	/* Port 5 supports rgmii with delays on MT7531BE, sgmii/802.3z on
+	 * MT7531AE.
+	 */
+	case 5:
+		if (!priv->p5_sgmii) {
 			phy_interface_set_rgmii(config->supported_interfaces);
 			break;
 		}
 		fallthrough;
 
-	case 6: /* 1st cpu port supports sgmii/8023z only */
+	/* Port 6 supports sgmii/802.3z. */
+	case 6:
 		__set_bit(PHY_INTERFACE_MODE_SGMII,
 			  config->supported_interfaces);
 		__set_bit(PHY_INTERFACE_MODE_1000BASEX,
@@ -2617,11 +2599,13 @@ static void mt7988_mac_port_get_caps(struct dsa_switch *ds, int port,
 	phy_interface_zero(config->supported_interfaces);
 
 	switch (port) {
-	case 0 ... 4: /* Internal phy */
+	/* Ports which are connected to switch PHYs. There is no MII pinout. */
+	case 0 ... 4:
 		__set_bit(PHY_INTERFACE_MODE_INTERNAL,
 			  config->supported_interfaces);
 		break;
 
+	/* Port 6 is connected to SoC's XGMII MAC. There is no MII pinout. */
 	case 6:
 		__set_bit(PHY_INTERFACE_MODE_INTERNAL,
 			  config->supported_interfaces);
@@ -2659,7 +2643,7 @@ static int mt7531_rgmii_setup(struct mt7530_priv *priv, u32 port,
 {
 	u32 val;
 
-	if (!mt7531_is_rgmii_port(priv, port)) {
+	if (priv->p5_sgmii) {
 		dev_err(priv->dev, "RGMII mode is not available for port %d\n",
 			port);
 		return -EINVAL;
@@ -2785,12 +2769,12 @@ mt753x_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
 	u32 mcr_cur, mcr_new;
 
 	switch (port) {
-	case 0 ... 4: /* Internal phy */
+	case 0 ... 4:
 		if (state->interface != PHY_INTERFACE_MODE_GMII &&
 		    state->interface != PHY_INTERFACE_MODE_INTERNAL)
 			goto unsupported;
 		break;
-	case 5: /* 2nd cpu port with phy of port 0 or 4 / external phy */
+	case 5:
 		if (priv->p5_interface == state->interface)
 			break;
 
@@ -2800,7 +2784,7 @@ mt753x_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
 		if (priv->p5_intf_sel != P5_DISABLED)
 			priv->p5_interface = state->interface;
 		break;
-	case 6: /* 1st cpu port */
+	case 6:
 		if (priv->p6_interface == state->interface)
 			break;
 
@@ -2903,7 +2887,7 @@ mt7531_cpu_port_config(struct dsa_switch *ds, int port)
 
 	switch (port) {
 	case 5:
-		if (mt7531_is_rgmii_port(priv, port))
+		if (!priv->p5_sgmii)
 			interface = PHY_INTERFACE_MODE_RGMII;
 		else
 			interface = PHY_INTERFACE_MODE_2500BASEX;
@@ -3055,7 +3039,7 @@ mt753x_setup(struct dsa_switch *ds)
 		mt7530_free_irq_common(priv);
 
 	if (priv->create_sgmii) {
-		ret = priv->create_sgmii(priv, mt7531_dual_sgmii_supported(priv));
+		ret = priv->create_sgmii(priv);
 		if (ret && priv->irq)
 			mt7530_free_irq(priv);
 	}
@@ -3093,6 +3077,36 @@ static int mt753x_set_mac_eee(struct dsa_switch *ds, int port,
 	return 0;
 }
 
+static void
+mt753x_conduit_state_change(struct dsa_switch *ds,
+			    const struct net_device *conduit,
+			    bool operational)
+{
+	struct dsa_port *cpu_dp = conduit->dsa_ptr;
+	struct mt7530_priv *priv = ds->priv;
+	int val = 0;
+	u8 mask;
+
+	/* Set the CPU port to trap frames to for MT7530. Trapped frames will be
+	 * forwarded to the numerically smallest CPU port whose conduit
+	 * interface is up.
+	 */
+	if (priv->id != ID_MT7530 && priv->id != ID_MT7621)
+		return;
+
+	mask = BIT(cpu_dp->index);
+
+	if (operational)
+		priv->active_cpu_ports |= mask;
+	else
+		priv->active_cpu_ports &= ~mask;
+
+	if (priv->active_cpu_ports)
+		val = CPU_EN | CPU_PORT(__ffs(priv->active_cpu_ports));
+
+	mt7530_rmw(priv, MT7530_MFC, CPU_EN | CPU_PORT_MASK, val);
+}
+
 static int mt7988_pad_setup(struct dsa_switch *ds, phy_interface_t interface)
 {
 	return 0;
@@ -3148,6 +3162,7 @@ const struct dsa_switch_ops mt7530_switch_ops = {
 	.phylink_mac_link_up	= mt753x_phylink_mac_link_up,
 	.get_mac_eee		= mt753x_get_mac_eee,
 	.set_mac_eee		= mt753x_set_mac_eee,
+	.conduit_state_change	= mt753x_conduit_state_change,
 };
 EXPORT_SYMBOL_GPL(mt7530_switch_ops);
 
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index 17e42d30fff4..80060cc740d2 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -41,8 +41,8 @@ enum mt753x_id {
 #define  UNU_FFP(x)			(((x) & 0xff) << 8)
 #define  UNU_FFP_MASK			UNU_FFP(~0)
 #define  CPU_EN				BIT(7)
-#define  CPU_PORT(x)			((x) << 4)
-#define  CPU_MASK			(0xf << 4)
+#define  CPU_PORT_MASK			GENMASK(6, 4)
+#define  CPU_PORT(x)			FIELD_PREP(CPU_PORT_MASK, x)
 #define  MIRROR_EN			BIT(3)
 #define  MIRROR_PORT(x)			((x) & 0x7)
 #define  MIRROR_MASK			0x7
@@ -683,11 +683,10 @@ struct mt7530_port {
 
 /* Port 5 interface select definitions */
 enum p5_interface_select {
-	P5_DISABLED = 0,
+	P5_DISABLED,
 	P5_INTF_SEL_PHY_P0,
 	P5_INTF_SEL_PHY_P4,
 	P5_INTF_SEL_GMAC5,
-	P5_INTF_SEL_GMAC5_SGMII,
 };
 
 struct mt7530_priv;
@@ -756,10 +755,13 @@ struct mt753x_info {
  *			registers
  * @p6_interface	Holding the current port 6 interface
  * @p5_intf_sel:	Holding the current port 5 interface select
+ * @p5_sgmii:		Flag for distinguishing if port 5 of the MT7531 switch
+ *			has got SGMII
  * @irq:		IRQ number of the switch
  * @irq_domain:		IRQ domain of the switch irq_chip
  * @irq_enable:		IRQ enable bits, synced to SYS_INT_EN
  * @create_sgmii:	Pointer to function creating SGMII PCS instance(s)
+ * @active_cpu_ports:	Holding the active CPU ports
  */
 struct mt7530_priv {
 	struct device		*dev;
@@ -775,7 +777,8 @@ struct mt7530_priv {
 	bool			mcm;
 	phy_interface_t		p6_interface;
 	phy_interface_t		p5_interface;
-	unsigned int		p5_intf_sel;
+	enum p5_interface_select p5_intf_sel;
+	bool			p5_sgmii;
 	u8			mirror_rx;
 	u8			mirror_tx;
 	struct mt7530_port	ports[MT7530_NUM_PORTS];
@@ -785,7 +788,8 @@ struct mt7530_priv {
 	int irq;
 	struct irq_domain *irq_domain;
 	u32 irq_enable;
-	int (*create_sgmii)(struct mt7530_priv *priv, bool dual_sgmii);
+	int (*create_sgmii)(struct mt7530_priv *priv);
+	u8 active_cpu_ports;
 };
 
 struct mt7530_hw_vlan_entry {