Subject: [PATCH net-next v4 10/10] net: airoha: Support multiple LAN/WAN interfaces for hw MAC address configuration

From: Lorenzo Bianconi <[email-masked]>
Date: Thu, 07 May 2026 23:21:53 +0200

The EN7581 and AN7583 SoCs provide registers to configure hardware LAN/WAN
MAC addresses, used to determine whether received traffic is destined for
this host or should be forwarded to another device.
The SoC hardware design assumes all interfaces configured as LAN (or WAN)
share a common upper MAC address, which is programmed into the
REG_FE_{LAN,WAN}_MAC_H register. The lower bytes of 'local' addresses can
be expressed as a range via the REG_FE_MAC_LMIN and REG_FE_MAC_LMAX
registers.
Previously, only a single interface was considered when programming these
registers. Extend the logic to derive the correct minimum and maximum
values for REG_FE_MAC_LMIN/REG_FE_MAC_LMAX when two or more interfaces are
configured as LAN or WAN.

Tested-by: Madhur Agrawal <[email-masked]>
Signed-off-by: Lorenzo Bianconi <[email-masked]>
---
 drivers/net/ethernet/airoha/airoha_eth.c | 73 +++++++++++++++++++++++++++-----
 1 file changed, 63 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 8617dd4f7932..fbfefd0ec355 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -71,20 +71,67 @@ static void airoha_qdma_irq_disable(struct airoha_irq_bank *irq_bank,
 	airoha_qdma_set_irqmask(irq_bank, index, mask, 0);
 }
 
-static void airoha_set_macaddr(struct airoha_gdm_dev *dev, const u8 *addr)
+static int airoha_set_macaddr(struct airoha_gdm_dev *dev, const u8 *addr)
 {
 	struct airoha_eth *eth = dev->eth;
-	u32 val, reg;
+	u8 ref_addr[ETH_ALEN] = {};
+	u32 reg, val, lmin, lmax;
+	int i;
+
+	lmin = (addr[3] << 16) | (addr[4] << 8) | addr[5];
+	lmax = lmin;
+
+	for (i = 0; i < ARRAY_SIZE(eth->ports); i++) {
+		struct airoha_gdm_port *port = eth->ports[i];
+		int j;
+
+		if (!port)
+			continue;
+
+		for (j = 0; j < ARRAY_SIZE(port->devs); j++) {
+			struct airoha_gdm_dev *iter_dev;
+			struct net_device *netdev;
+
+			iter_dev = port->devs[j];
+			if (!iter_dev || iter_dev == dev)
+				continue;
+
+			if (airoha_is_lan_gdm_dev(iter_dev) !=
+			    airoha_is_lan_gdm_dev(dev))
+				continue;
+
+			netdev = iter_dev->dev;
+			if (netdev->reg_state != NETREG_REGISTERED)
+				continue;
+
+			ether_addr_copy(ref_addr, netdev->dev_addr);
+			val = (netdev->dev_addr[3] << 16) |
+			      (netdev->dev_addr[4] << 8) | netdev->dev_addr[5];
+			if (val < lmin)
+				lmin = val;
+			if (val > lmax)
+				lmax = val;
+		}
+	}
+
+	if (!is_zero_ether_addr(ref_addr) && memcmp(ref_addr, addr, 3)) {
+		/* According to the HW design, hw mac address MS bits
+		 * must be the same for each net_device with the same
+		 * LAN/WAN configuration.
+		 */
+		return -EINVAL;
+	}
 
 	reg = airoha_is_lan_gdm_dev(dev) ? REG_FE_LAN_MAC_H : REG_FE_WAN_MAC_H;
 	val = (addr[0] << 16) | (addr[1] << 8) | addr[2];
 	airoha_fe_wr(eth, reg, val);
 
-	val = (addr[3] << 16) | (addr[4] << 8) | addr[5];
-	airoha_fe_wr(eth, REG_FE_MAC_LMIN(reg), val);
-	airoha_fe_wr(eth, REG_FE_MAC_LMAX(reg), val);
+	airoha_fe_wr(eth, REG_FE_MAC_LMIN(reg), lmin);
+	airoha_fe_wr(eth, REG_FE_MAC_LMAX(reg), lmax);
 
 	airoha_ppe_init_upd_mem(dev);
+
+	return 0;
 }
 
 static void airoha_set_gdm_port_fwd_cfg(struct airoha_eth *eth, u32 addr,
@@ -1792,13 +1839,18 @@ static int airoha_dev_stop(struct net_device *netdev)
 static int airoha_dev_set_macaddr(struct net_device *netdev, void *p)
 {
 	struct airoha_gdm_dev *dev = netdev_priv(netdev);
+	struct sockaddr *addr = p;
 	int err;
 
-	err = eth_mac_addr(netdev, p);
+	err = eth_prepare_mac_addr_change(netdev, p);
 	if (err)
 		return err;
 
-	airoha_set_macaddr(dev, netdev->dev_addr);
+	err = airoha_set_macaddr(dev, addr->sa_data);
+	if (err)
+		return err;
+
+	eth_commit_mac_addr_change(netdev, p);
 
 	return 0;
 }
@@ -1903,6 +1955,7 @@ static int airoha_dev_init(struct net_device *netdev)
 {
 	struct airoha_gdm_dev *dev = netdev_priv(netdev);
 	struct airoha_gdm_port *port = dev->port;
+	int err;
 
 	switch (port->id) {
 	case AIROHA_GDM3_IDX:
@@ -1922,12 +1975,12 @@ static int airoha_dev_init(struct net_device *netdev)
 	}
 
 	airoha_dev_set_qdma(dev);
-	airoha_set_macaddr(dev, netdev->dev_addr);
+	err = airoha_set_macaddr(dev, netdev->dev_addr);
+	if (err)
+		return err;
 
 	if (!airoha_is_lan_gdm_dev(dev) &&
 	    (port->id == AIROHA_GDM3_IDX || port->id == AIROHA_GDM4_IDX)) {
-		int err;
-
 		err = airoha_set_gdm2_loopback(dev);
 		if (err) {
 			dev->flags &= ~PRIV_FLAG_WAN;

-- 
2.54.0