Feature Request: I2C/SMBus support for getting transceiver information

[laf0rge]

This Linux driver does not expose the SMBus/I2C via the standard linux kernel features, so ethtool --module-info is not supported.

On the other hand, it seems the open source DPDK driver released by Aquantia does support this feature, so it would be great if this could be added to the Linux driver, too.

The purpoose would be to detect the SFP transceiver type used, as well as the laser output power, receive power level, alarms, etc. - an example output of this is seen at https://docs.nvidia.com/networking-ethernet-software/cumulus-linux-40/Monitoring-and-Troubleshooting/Troubleshooting-Network-Interfaces/Monitoring-Interfaces-and-Transceivers-Using-ethtool/#monitor-switch-port-sfpqsfp-hardware-information-using-ethtool

AFAICT, all that is needed for making this wealth of information available is to expose I2C/SMbus operations in the driver - all the decoding / parsing is generic and implemented by higher layer tools.

[lorenz]

I reverse-engineered this (didn't know about the fact that DPDK has it, would've been helpful, I REd it from a Dell diagnostic utility) and contributed it upstream. It's going to land in Linux 6.13.

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=853a2944aaf394ff425ed4821231918cb60d4ff9