PCIe 0 x4 Lane Reversal

I’m debisgning a custom carrier board for Orin NX and Orin Nano.
In my design PCIe 0 x4 connects to an M.2 Type M slot. I’d like to use PCIe Lane reversal in order to make layout easier and improve signal quality. So Orin PCIe0 Lane 0 would connect to M.2 Lane 3, Orin Lane 1 would connect to M.2 Lane 2, etc., both for TX and RX.

  • Is this supported? Do I need to do something in order to activate it?
  • Does this also work if the M.2 card plugged into that slot has only one or two lanes?
  • Do I have other problems or disadvantages by using lane reversal?

Hi, please refer to below topics for such questions.