The command only supports the new PCIe library that utilizes the classes pcie-downstream-port and pcie-downstream-port-legacy to build up the PCIe topology. Endpoints based on the old PCIe library are also printed out if they are connected to a pcie-downstream-port-legacy device. Upstream ports of switches based on the old PCIe library are printed as well. But its downstream ports and devices below it are skipped.
The -skip-info argument can be used to hide the info column in the table that contains the class description of the device.
The namespace argument can be used to only traverse PCIe hierarchies where the host bridge is part of the namespace.