[PATCH 4.19 70/71] net: dsa: read mac address from DT for slave device

[Greg Kroah-Hartman]

From: Xiaofei Shen <xiaofeis@xxxxxxxxxxxxxx>

commit a2c7023f7075ca9b80f944d3f20f60e6574538e2 upstream.

Before creating a slave netdevice, get the mac address from DTS and
apply in case it is valid.

Signed-off-by: Xiaofei Shen <xiaofeis@xxxxxxxxxxxxxx>
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Pali Rohár <pali@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 include/net/dsa.h |    1 +
 net/dsa/dsa2.c    |    1 +
 net/dsa/slave.c   |    5 ++++-
 3 files changed, 6 insertions(+), 1 deletion(-)

--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -196,6 +196,7 @@ struct dsa_port {
 	unsigned int		index;
 	const char		*name;
 	const struct dsa_port	*cpu_dp;
+	const char		*mac;
 	struct device_node	*dn;
 	unsigned int		ageing_time;
 	u8			stp_state;
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -261,6 +261,7 @@ static int dsa_port_setup(struct dsa_por
 	int err = 0;
 
 	memset(&dp->devlink_port, 0, sizeof(dp->devlink_port));
+	dp->mac = of_get_mac_address(dp->dn);
 
 	if (dp->type != DSA_PORT_TYPE_UNUSED)
 		err = devlink_port_register(ds->devlink, &dp->devlink_port,
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1313,7 +1313,10 @@ int dsa_slave_create(struct dsa_port *po
 	slave_dev->features = master->vlan_features | NETIF_F_HW_TC;
 	slave_dev->hw_features |= NETIF_F_HW_TC;
 	slave_dev->ethtool_ops = &dsa_slave_ethtool_ops;
-	eth_hw_addr_inherit(slave_dev, master);
+	if (port->mac && is_valid_ether_addr(port->mac))
+		ether_addr_copy(slave_dev->dev_addr, port->mac);
+	else
+		eth_hw_addr_inherit(slave_dev, master);
 	slave_dev->priv_flags |= IFF_NO_QUEUE;
 	slave_dev->netdev_ops = &dsa_slave_netdev_ops;
 	slave_dev->switchdev_ops = &dsa_slave_switchdev_ops;