PCIEx4 for Jetson NX and Nano

What is the different of PCIEx4 interface for Jetson NX and Nano.
In my design, I used a PCIE switch IC(Asmedia ASM1806) that is a PCIEx2 to 4 PCIEx1 IC to support 4 PCIEx1 device. In Jetson NX, the 4 PCIEx1 device can work fine, but in Jetson Nano,the PCIEx1 device does not be identified.

Hi, did you check the doc: https://developer.nvidia.com/jetson-xavier-nx-and-jetson-nano-interface-comparison-migration-application-note-v10 ?

“Jetson Xavier NX supports two PCIe interfaces: A x1 lane interface and a x4 lane interface (can be x2 or x1 instead) at the module pins. Jetson Nano supports only the x4 lane interface (can be x2 or x1 instead).at the module pins. Jetson Xavier NX supports both Root Port and Endpoint operation on the x4 interface (only Root Port on the x1) where Jetson Nano only supports Root Port operation.”

Yes, I had check the doc. The ASM1806 is connected with root port. It should be OK for Nano board. In fact when I use the command lspci, the terminal list PCI Bridge ASM1806. But the PCIE devices can not be detected under the ASM1806 for Nano.

Are you saying that the PCIe switch’s upstream port and 4 downstream ports are listed in the lspci but not the 4 endpoints connected to 4 downstream ports of the switch? If yes, this is weird. I’m afraid we can’t do much here as the link up issue is between PCIe switch and its downstream devices (and not between Tegra’s root port and the upstream port of the switch).
Nevertheless, could you please share the output of ‘sudo lspci -vvvv’? I wanted to see if any of the PCIe switch’s downstream ports have ‘DLActiv+’ which would indicate that link did come up with the endpoints but at a later point of time.

I use the same carrier board,just changed the NX and Naon board.
For NX board, the LAN IC i210 can work fine. For Nano board,the LAN IC i210 can not be identiified.
The message of “lspci-vvvv” for NX and Nano board is list in Nano.txt and NX.txt.

nano.txt (6.4 KB) NX.txt (7.2 KB)

There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one.


Please share following information for both Nx and Nano,

  1. sudo lspci -vvv
  2. sudo lspci -tv
  3. dmesg logs
  4. cat /proc/iomem
  5. setpci -s 0000:05:00.0 #On Nano
    setpci -s 0005:05:00.0 #On Nx