ROCK3A PCIE20 LTSSM fail

#1

I make a PCI baremetal driver in my OS for ROCK 3A. The NVME can work OK in PCIE30, but when I enable PCIE20, PCIE host’s LTSSM is fail:

PCIe Linking... LTSSM is 0x3
PCIe Linking... LTSSM is 0x3
PCIe Linking... LTSSM is 0x3
PCIe Linking... LTSSM is 0x3
PCIe Linking... LTSSM is 0x3
PCIe Link Fail, LTSSM is 0x3
PCIe Linking... LTSSM is 0x3
PCIe Linking... LTSSM is 0x3
PCIe Linking... LTSSM is 0x3
PCIe Linking... LTSSM is 0x3
PCIe Linking... LTSSM is 0x3
PCIe Link Fail, LTSSM is 0x3

There is PHY, CLK, Reset, GPIO, and Regulator driver in PCI, Which one is more likely error?

#2

Try to remove the rst_gpio, the error is show in linux, too.