Using PCI interface on EM120R-GL with a Freescale iMX6Q

I have a board with an EM120R-GL connected via both USB and PCI express to an iMX6Q cpu module. The USB interface works just fine, but I have trouble getting data communication working using the PCI interface. The hardware design should be solid with all the correct trace impedances and connections, and the PCI interface has been correctly selected with the relevant AT+QFFG=“data_interface”,1,0 command. The PCI link just does not seem to come up.
Has anyone successfully connected an EM120R-GL to an iMX6Q processor using the PCI express bus? Should the link be Gen1 or Gen2?


You are advised to set AT+QCFG=“data_interface”,1,0, and then restart the device. After the device is powered on, run lspci to check whether the PCIE interface is identified. Thank you.

I used just that AT command and restarted the modem, but the pci express link did not come up and the modem was not listed with lspci. The usb command ports still worked as before, but the network interface just did not show up on the pci express link.
Should the pci interface on this modem work (and be backwards compatible) with a pci controller that prefers to work as a Gen1 device?