Failed to detect USB on MiniPCIe connector which is connected to PCIe C9 - Jetson Orin NX / Orin Nano with Jetpack6.0

Hi,

We are trying to connect an LTE module card (USB Bus based) on a miniPcie connector on our custom carrier board.

It works with a PCIE bus-based card. But with a USB bus-based card (an LTE module card) it is not getting detected.
The cause of the problem is the PEX_RST is low after the system boots up. The USB bus-based card uses the PEX_RST signal as a reset input.

By adding “nvidia,disable-power-down” to PCIe node DT entry in jetpack 5.1.1 we were able to detect the LTE module card (USB Bus based) but when we try the same change in Jetpack6.0 it is not working.

Can you please suggest how to keep the PEX_RST high when there is no PCIE end points detected.

This post might help.

Though I am not quite sure what does that mean USB Bus based or PCIE bus-based.