Pcie device can not be recongnized

I have made a custom carrier board for the Jetson AGX Xavier.This is my hardware design.

When the board is powered up, it can’t find pcie device(Tsi721) and there is some pcie bus errors.

搜狗截图22年06月01日1406_1930×83 5.45 KB

Q1:Is PEX_CLK5_P/N HCSL or LVDS level?

Q2:Whether the reset time（PEX_L5_RST_N） can be modified?

Q3:When the pcie device link down, how to let pcie device link again?