pcie can't enter L0 state

Use Quartus 9.0 and SOPC buiding an system of PICE+DMA+on chip memory。

full compile the design,program it to S2GX30DF with custom logic of LED,

the board hold on Polling.Compliance State，and can't enter L0 state,so it can not work,

anyone can give some advice to handle the problem?

thanks very much.