From: Jakub Kicinski <kuba@xxxxxxxxxx> [ Upstream commit bd7f14df9492e7d3772812a215fca66e6737e598 ] Ian reports that after upgrade from v5.8.14 to v5.9 only one of his 4 ixgbe netdevs appear in the system. Quoting the comment on ixgbe_x550em_a_has_mii(): * Returns true if hw points to lowest numbered PCI B:D.F x550_em_a device in * the SoC. There are up to 4 MACs sharing a single MDIO bus on the x550em_a, * but we only want to register one MDIO bus. This matches the symptoms, since the return value from ixgbe_mii_bus_init() is no longer ignored we need to handle the higher ports of x550em without an error. Fixes: 09ef193fef7e ("net: ethernet: ixgbe: check the return value of ixgbe_mii_bus_init()") Reported-by: Ian Kumlien <ian.kumlien@xxxxxxxxx> Tested-by: Ian Kumlien <ian.kumlien@xxxxxxxxx> Acked-by: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx> Link: https://lore.kernel.org/r/20201016232006.3352947-1-kuba@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c @@ -901,15 +901,13 @@ static bool ixgbe_x550em_a_has_mii(struc **/ s32 ixgbe_mii_bus_init(struct ixgbe_hw *hw) { + s32 (*write)(struct mii_bus *bus, int addr, int regnum, u16 val); + s32 (*read)(struct mii_bus *bus, int addr, int regnum); struct ixgbe_adapter *adapter = hw->back; struct pci_dev *pdev = adapter->pdev; struct device *dev = &adapter->netdev->dev; struct mii_bus *bus; - bus = devm_mdiobus_alloc(dev); - if (!bus) - return -ENOMEM; - switch (hw->device_id) { /* C3000 SoCs */ case IXGBE_DEV_ID_X550EM_A_KR: @@ -922,16 +920,23 @@ s32 ixgbe_mii_bus_init(struct ixgbe_hw * case IXGBE_DEV_ID_X550EM_A_1G_T: case IXGBE_DEV_ID_X550EM_A_1G_T_L: if (!ixgbe_x550em_a_has_mii(hw)) - return -ENODEV; - bus->read = &ixgbe_x550em_a_mii_bus_read; - bus->write = &ixgbe_x550em_a_mii_bus_write; + return 0; + read = &ixgbe_x550em_a_mii_bus_read; + write = &ixgbe_x550em_a_mii_bus_write; break; default: - bus->read = &ixgbe_mii_bus_read; - bus->write = &ixgbe_mii_bus_write; + read = &ixgbe_mii_bus_read; + write = &ixgbe_mii_bus_write; break; } + bus = devm_mdiobus_alloc(dev); + if (!bus) + return -ENOMEM; + + bus->read = read; + bus->write = write; + /* Use the position of the device in the PCI hierarchy as the id */ snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mdio-%s", ixgbe_driver_name, pci_name(pdev));