net: lan966x: avoid unregistering netdev on register failure

lan966x_probe_port() stores the newly allocated net_device in the
port before calling register_netdev(). If register_netdev() fails,
the probe error path calls lan966x_cleanup_ports(), which sees
port->dev and calls unregister_netdev() for a device that was never
registered.

Destroy the phylink instance created for this port and clear port->dev
before returning the registration error. The common cleanup path now skips
ports without port->dev before reaching the registered netdev cleanup, so
it only handles ports that reached the registered-netdev lifetime.

This also avoids treating an uninitialized FDMA netdev and the failed port
as a NULL == NULL match in the common cleanup path.

Fixes: d28d6d2e37d1 ("net: lan966x: add port module support")
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Link: https://patch.msgid.link/20260506124331.31945-1-mhun512@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 47752d3fde0b108ecb0817153ca3e16ad9f98bf2..1179a6e127c52772f3085e5630bb33552bfcd00a 100644 (file)
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -749,11 +749,10 @@ static void lan966x_cleanup_ports(struct lan966x *lan966x)
 
        for (p = 0; p < lan966x->num_phys_ports; p++) {
                port = lan966x->ports[p];
-               if (!port)
+               if (!port || !port->dev)
                        continue;
 
-               if (port->dev)
-                       unregister_netdev(port->dev);
+               unregister_netdev(port->dev);
 
                lan966x_xdp_port_deinit(port);
                if (lan966x->fdma && lan966x->fdma_ndev == port->dev)
@@ -873,6 +872,9 @@ static int lan966x_probe_port(struct lan966x *lan966x, u32 p,
        err = register_netdev(dev);
        if (err) {
                dev_err(lan966x->dev, "register_netdev failed\n");
+               phylink_destroy(phylink);
+               port->phylink = NULL;
+               port->dev = NULL;
                return err;
        }