[PATCH 5.18 092/339] net: lan966x: check devm_of_phy_get() for -EDEFER_PROBE

[Greg Kroah-Hartman]

From: Michael Walle <michael@xxxxxxxx>

[ Upstream commit b58cdd4388b1d8f5bee9f5a3897a7e780d1eaa48 ]

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@xxxxxxxx>
Link: https://lore.kernel.org/r/20220525231239.1307298-1-michael@xxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/microchip/lan966x/lan966x_main.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 05f6dcc9dfd5..f180a157eea4 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -1080,8 +1080,13 @@ 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]);
 	}
-- 
2.35.1