One of the basic tenants of the open source community is to provide the community some access to query and to report bugs.
I invite anyone in the Mellanox Community at large to comment on how well this is provided. I ask this question since Ib which is the
bread and butter here is open source. But I digress...
I have mlxlink. It works fine to access my SB7700 once the subnet manager is up and running. The switch I want to configure the ASIC
on is right there in /dev/mst as I would expect. Using the Mellanox Firmware Tools I can use mlxreg to "show" all the registers I can see with
"show reg". The problem is, mlxlink cannot access any of the ports, or the device for that matter because it cant find PDDR. I am not really
surprised since mlxreg doesn't find/display that register in the first place.
Since Appendix C: in the mlxlink user manual clearly states it should access the ports on the remote switch and shows an example.
Why doesn't it work as advertised?
Since mlxlink is not product meant for end user for design in customers (I assume such as yourself) - you should contact your Mellanox FAE and work with him on this issue/question.
I see that you already have a case opened with one of our FAE's.