Intel i219-LM Had Only Been Running At ~60% Of Maximum Speed Due To Linux Driver Bug

If you rely on an Intel I219-LM Gigabit Ethernet adapter, you will want to look forward to upgrading your Linux kernel build soon... A fix was committed today after Intel engineers discovered this particular Ethernet chipset had only been running at around 60% of its maximum speed due to a regression introduced back in 2020.

Intel's Linux networking engineers have landed a fix today to Linux 6.3 Git, which in turn is sure to be back-ported to stable supported kernel series. Since the release of Linux 5.8 in mid-2020, this Ethernet adapter had been running at around 60% of its advertised potential due to an e1000e driver regression.

The issue stems from TCP Segment Offload (TSO) not being properly disabled even though the change in Linux 5.8 attempted to do so. Now with Linux 6.3 -- and to be back-ported to supported stable series -- TSO is being properly disabled at driver probe time for the i219-LM. TSO needs to be disabled for this particular adapter for PCIe interfaces or at 10/100 speeds to avoid "hardware issues" with this particular chipset.

This commit landed in the kernel tree a few minutes ago to properly address the situation. If all goes well, Linux 6.3 stable will be out this weekend.