P3584 10G Dongle: How to persist Secondary (sm 0) mode across power cycles?

Autonomous Vehicles DRIVE AGX Thor DRIVE AGX Thor General
1

DRIVE OS Version: 7.0.3

Issue Description:

Platform: NVIDIA Drive AGX Thor / DRIVE OS 7.0.3
Hardware: P3584 10G Dongle, firmware 7.1.8

3584 2.7>pinfo

88Q4364: Register Reads
Reg 1.0 Val:0x2041
Reg 1.1 Val:0x2
R:0x1E300 V:0x6

Base-T1 Mode:Master
Speed:10G
Link Down

FW Version:7.1.8
candidateRevision:0x0

AQR113C: Register Reads
Reg 1E.C842 Val:0x3311
Reg 1E.C885 Val:0x74
Reg 1E.20 Val:0x506

ADC Vals:300,290

PWM val:84

Background

The P3584 10G dongle defaults to Primary mode for the 88Q4364 Base-T1 PHY after every power cycle. As documented, connecting it to the Drive AGX Thor’s Base-T1 port requires
setting it to Secondary mode via sm 0 in the UART console. This works correctly — after sm 0 (without a PHY reset via rphy), the 88Q4364 re-negotiates as Slave and the T1 link
comes up.

ref: P3960 Network Topology — NVIDIA DriveOS 7.0.3 Linux SDK Developer Guide

Problem

The dongle reverts to Primary mode on every power cycle, requiring a manual sm 0 command to restore Secondary mode. This is a blocking issue in setups where:

  • The board undergoes regular power resets (not just software reboots)
  • The dongle is not always connected via USB to a host machine, making serial console access unreliable (besides, it requires CDC kernel modules)

A host-side startup script is not a viable general solution for these reasons.

Questions

  1. Is there a way to persist the Secondary role setting to the dongle’s NVRAM or OTP so that it boots in Secondary mode by default without requiring sm 0 after every power cycle?
  2. If not currently supported, is a firmware update planned that would expose a persistent configuration command (e.g., something like sm 0 save or a dedicated saveconfig command)?
  3. Alternatively, is there an undocumented command in the current 7.1.8 firmware that writes the T1 role to non-volatile storage?

Thanks in advance for any guidance on the topic

4

Dear @boris.savelev ,

Let me confirm internally with engineering team to confirm the feasibility and update you.

5

You need to issue sm 0 on dongle uart console after every power cycle. We don’t have plans to add any persistent storage configuration command.

6

Thanks for the reply. Maybe it’s possible to put Thor MGBE0 to the Secondary mode?

8

Dear @boris.savelev ,
Please file a seperate topic for issues/query related to mgbe to avoid cluttering of topics/issues. Thanks