PCIe x1 in arria 10 is not working

Hi,
We are using the Arria10 SOC development Kit and we are using the reference design provided in the below link to test Arria 10 SOC development kit as root port.
https://releases.rocketboards.org/release/2017.05/pcierd/hw/a10_soc_devkit_pcie_gen2x8.tar.gz
We have have tested PCIex8 and PCIex4 design it is working fine.But if we recompile the same design for PCIex1 it is not working and kernel hangs while enabling the device.

Please help me with above issue.

Regards,
Rakshith