imx8mp pcie eye pattern test fail

[jiangyaqiang]

Hi :

My board PCIE eye pattern test fail at something, as bellow:

The "low Limit" is a litter too fast. 

which register should I tune to pass it ?

I have attachment the complete test report.

[igorpadykov]

Hi Yaqiang

reason may incorrect testing measurements, may be recommended to recheck them using AN12444

PCIe Certification Guide for i.MX8 Serials

Best regards
igor

[jiangyaqiang]

Hi igor:

Thanks.

I have checked the file , there is one parameter using in the file: pcie_cz_enabled=yes,

I can't find it in kernel, could you tell me what's the parameter used for ?

BTW, We have test the EVK board, it passed, any we use the same kernel and config in my board, it fail, the fail is a very little margin, so I want to know what register is relative to the fail ?