# \[PATCH net 4/5\] ixgbe: Document how to enable NBASE-T support - From: Tony Nguyen \ - Date: 2021-12-15 19:35:52 - List: netdev - Page: https://ratatoskr.run/netdev/2021/12/11218985 - Thread: https://ratatoskr.run/netdev/2021/12/11218981/t.md ```text From: Robert Schlabbach Commit a296d665eae1 ("ixgbe: Add ethtool support to enable 2.5 and 5.0 Gbps support") introduced suppression of the advertisement of NBASE-T speeds by default, according to Todd Fujinaka to accommodate customers with network switches which could not cope with advertised NBASE-T speeds, as posted in the E1000-devel mailing list: https://sourceforge.net/p/e1000/mailman/message/37106269/ However, the suppression was not documented at all, nor was how to enable NBASE-T support. Properly document the NBASE-T suppression and how to enable NBASE-T support. Fixes: a296d665eae1 ("ixgbe: Add ethtool support to enable 2.5 and 5.0 Gbps support") Reported-by: Robert Schlabbach Signed-off-by: Robert Schlabbach Signed-off-by: Tony Nguyen --- .../device_drivers/ethernet/intel/ixgbe.rst | 16 ++++++++++++++++ drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 4 ++++ 2 files changed, 20 insertions(+) diff --git a/Documentation/networking/device_drivers/ethernet/intel/ixgbe.rst b/Documentation/networking/device_drivers/ethernet/intel/ixgbe.rst index f1d5233e5e51..0a233b17c664 100644 --- a/Documentation/networking/device_drivers/ethernet/intel/ixgbe.rst +++ b/Documentation/networking/device_drivers/ethernet/intel/ixgbe.rst @@ -440,6 +440,22 @@ NOTE: For 82599-based network connections, if you are enabling jumbo frames in a virtual function (VF), jumbo frames must first be enabled in the physical function (PF). The VF MTU setting cannot be larger than the PF MTU. +NBASE-T Support +--------------- +The ixgbe driver supports NBASE-T on some devices. However, the advertisement +of NBASE-T speeds is suppressed by default, to accommodate broken network +switches which cannot cope with advertised NBASE-T speeds. Use the ethtool +command to enable advertising NBASE-T speeds on devices which support it:: + + ethtool -s eth? advertise 0x1800000001028 + +On Linux systems with INTERFACES(5), this can be specified as a pre-up command +in /etc/network/interfaces so that the interface is always brought up with +NBASE-T support, e.g.:: + + iface eth? inet dhcp + pre-up ethtool -s eth? advertise 0x1800000001028 || true + Generic Receive Offload, aka GRO -------------------------------- The driver supports the in-kernel software implementation of GRO. GRO has diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 0f9f022260d7..45e2ec4d264d 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -5531,6 +5531,10 @@ static int ixgbe_non_sfp_link_config(struct ixgbe_hw *hw) if (!speed && hw->mac.ops.get_link_capabilities) { ret = hw->mac.ops.get_link_capabilities(hw, &speed, &autoneg); + /* remove NBASE-T speeds from default autonegotiation + * to accommodate broken network switches in the field + * which cannot cope with advertised NBASE-T speeds + */ speed &= ~(IXGBE_LINK_SPEED_5GB_FULL | IXGBE_LINK_SPEED_2_5GB_FULL); } -- 2.31.1 ```