This is a note to let you know that I've just added the patch titled net: stmmac: Handle disabled MDIO busses from devicetree to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-stmmac-handle-disabled-mdio-busses-from-devicetr.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit db98cd88d3a8f33000e013c9b28a18b2d7cab663 Author: Andrew Halaney <ahalaney@xxxxxxxxxx> Date: Tue Dec 12 16:18:33 2023 -0600 net: stmmac: Handle disabled MDIO busses from devicetree [ 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> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c index ecc7f4842f849..d9b76e1e09493 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c @@ -459,7 +459,11 @@ int stmmac_mdio_register(struct net_device *ndev) 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_probe(dev, err, "Cannot register the MDIO bus\n"); goto bus_register_fail; }