4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andrew Halaney <ahalaney@xxxxxxxxxx>
[ Upstream commit e23c0d21ce9234fbc31ece35663ababbb83f9347 ]
Many hardware configurations have the MDIO bus disabled, and are instead
using some other MDIO bus to talk to the MAC's phy.
of_mdiobus_register() returns -ENODEV in this case. Let's handle it
gracefully instead of failing to probe the MAC.
Fixes: 47dd7a540b8a ("net: add support for STMicroelectronics Ethernet controllers.")
Signed-off-by: Andrew Halaney <ahalaney@xxxxxxxxxx>
Reviewed-by: Serge Semin <fancer.lancer@xxxxxxxxx>
Link: https://lore.kernel.org/r/20231212-b4-stmmac-handle-mdio-enodev-v2-1-600171acf79f@xxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -360,7 +360,11 @@ int stmmac_mdio_register(struct net_devi
new_bus->parent = priv->device;
err = of_mdiobus_register(new_bus, mdio_node);
- if (err != 0) {
+ if (err == -ENODEV) {
+ err = 0;
+ dev_info(dev, "MDIO bus is disabled\n");
+ goto bus_register_fail;
+ } else if (err) {
dev_err(dev, "Cannot register the MDIO bus\n");
goto bus_register_fail;
}
