Issue with Intel X710-DA2/DA4 on LattePanda MU Lite Carrier – Only One Port Active

Hi,

We are planning to use the LattePanda MU in our crate control system. but I have encountered an issue when integrating the Intel X710-DA2 (dual-port) or X710-DA4 (quad-port) Ethernet adapters. Specifically, only the first optical port works, while the others report "cable unplugged" or fail to initialize.

System Configuration:

Platform: LattePanda MU (N100) + Lite Carrier

Ethernet Adapter: Intel Ethernet Network Adapter X710-DA2 (or X710-DA4)

Operating System: Ubuntu 24.04 / Windows 11

Problem Description:

Only the first optical port on the X710-DA2/DA4 works, and the others are not functional.

When testing on Ubuntu and Windows, the first port achieves full-speed operation, while the remaining ports report "cable unplugged."

The issue appears to be related to the BIOS configuration, as the BIOS recognizes only a single MAC address (the X710-DA2 should have two MAC addresses, and the X710-DA4 should have four). I have also noticed the following logs when run "dmesg | grep i40e":

[    8.590730] i40e 0000:04:00.1: failed to get phy cap., ret =  -EIO last_status =  OK

Findings and Troubleshooting Steps:

BIOS Configuration:
From the BIOS, it appears that only one MAC address is recognized for the X710-DA2. X710-DA2 should have two MAC addresses, and the X710-DA4 should have four, but only one is being initialized.

BIOS version: [DFLT]

I suspect that the issue may be related to how the PCIe lanes are allocated or a configuration setting in the BIOS.

Driver Loading:
I have verified that the i40e driver is loaded correctly, and the system recognizes both ports during boot. However, the second port fails to establish a connection (PHY initialization failure).

Power Supply:
I have confirmed that I am using a 12V power supply, and the power is stable. However, I am aware that the X710-DA4 requires PCIe x8 bandwidth, and the LattePanda MU's Lite Carrier may be limiting the available bandwidth to x4, but it could not contribute to the issue.

Questions:

Are there any known BIOS settings or updates that might address the issue of multi-port recognition for Intel X710 adapters on the LattePanda MU?

Could there be a limitation in the PCIe lane allocation that is causing only the first port to initialize properly?

Do you have any recommendations or fixes to ensure all ports on the X710-DA2/DA4 are functional?

I would appreciate any guidance or suggestions you can offer to resolve this issue.

Thank you for your support!

Best regards,

Jie