From: Piotr Gardocki <redacted>

In some cases it is possible for kernel to come with request
to change primary MAC address to the address that is actually
already set on the given interface.

If the old and new MAC addresses are equal there is no need
for going through entire routine, including AdminQ and
waitqueue.

This patch adds proper check to return fast from the function
in these cases. The same check can also be found in i40e and
ice drivers.

An example of such case is adding an interface to bonding
channel in balance-alb mode:
modprobe bonding mode=balance-alb miimon=100 max_bonds=1
ip link set bond0 up
ifenslave bond0 <eth>

Signed-off-by: Piotr Gardocki <redacted>
Reviewed-by: Michal Swiatkowski <redacted>
Tested-by: Rafal Romanowski <redacted>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/iavf/iavf_main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 2de4baff4c20..420aaca548a0 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c

@@ -1088,6 +1088,12 @@ static int iavf_set_mac(struct net_device *netdev, void *p)
 	if (!is_valid_ether_addr(addr->sa_data))
 		return -EADDRNOTAVAIL;
 
+	if (ether_addr_equal(netdev->dev_addr, addr->sa_data)) {
+		netdev_dbg(netdev, "already using mac address %pM\n",
+			   addr->sa_data);
+		return 0;
+	}
+
 	ret = iavf_replace_primary_mac(adapter, addr->sa_data);
 
 	if (ret)

-- 
2.38.1