AM5728: AM5728 PCIe force GEN1 operation

Part Number:AM5728

Hi all,

Is there a way to force PCIe_SS{1,2} controller to operate with GEN1 (2.5Gb) speed?

I only have found MAX_LINK_SPEEDS [3:0] RW equal to 0x2 -> GEN2. ( PCIECTRL_EP_DBICS_LNK_CAP - 0x5180 007C register at AM5728 - SPRUHZ6G). 

Setting it to 0x1 does not bring any change, since I do read 0x2 afterwards.

I need to force GEN1 operational speed on this port because of PCIe switch problem (Pericom) connected to it. The switch sometimes is not correctly recognized - LTSSM fails for this port.

Best regards,

Lukasz