net: lan966x: check devm_of_phy_get() for -EDEFER_PROBE

At the moment, if devm_of_phy_get() returns an error the serdes
simply isn't set. While it is bad to ignore an error in general, there
is a particular bug that network isn't working if the serdes driver is
compiled as a module. In that case, devm_of_phy_get() returns
-EDEFER_PROBE and the error is silently ignored.

The serdes is optional, it is not there if the port is using RGMII, in
which case devm_of_phy_get() returns -ENODEV. Rearrange the error
handling so that -ENODEV will be handled but other error codes will
abort the probing.

Fixes: d28d6d2e37d1 ("net: lan966x: add port module support")
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20220525231239.1307298-1-michael@walle.cc
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 6ad68b4..5784c41 100644 (file)
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -1120,8 +1120,13 @@ static int lan966x_probe(struct platform_device *pdev)
                lan966x->ports[p]->fwnode = fwnode_handle_get(portnp);
 
                serdes = devm_of_phy_get(lan966x->dev, to_of_node(portnp), NULL);
-               if (!IS_ERR(serdes))
-                       lan966x->ports[p]->serdes = serdes;
+               if (PTR_ERR(serdes) == -ENODEV)
+                       serdes = NULL;
+               if (IS_ERR(serdes)) {
+                       err = PTR_ERR(serdes);
+                       goto cleanup_ports;
+               }
+               lan966x->ports[p]->serdes = serdes;
 
                lan966x_port_init(lan966x->ports[p]);
        }