Mellanox NIC ethtool SFP signal levels

[Joe Botha]

Hi

Using PVE kernel 5.13.19-6-pve and the latest firmware + drivers for Mellanox Dx6 NIC, I can't seem to get signal levels from an SFP using ethtool

ethtool -m enp1s0f1
Laser output power : 0.0000 mW / -inf dBm
Receiver signal OMA : 0.0000 mW / -inf dBm

It has link status, and I can get signal levels from the switch side.

ethtool -i enp1s0f1
driver: mlx5_core
version: 5.5-1.0.3
firmware-version: 22.32.2004 (MT_0000000356)

I also tried using pve-kernel-5.15.27-1-pve - same story.

Any ideas to fix this?