TMS320C6678: NDK send problem

Part Number: TMS320C6678

Hi

Board: customized board

OS: Win7

I have an "SRIO+NDK" project that SRIO and NDK worked at the same time correctly(I see the data that FPGA writes in the DSP memory and PING the DSP IP number by PC).

Now I want to send packets from DSP to PC and a problem happened, I can PING the DSP by PC but the DSP didn't send the data(The "send()" function return value "-1").

What should I check for debugging?

I should mention that I change the reference clock from 312.5Mhz to 250MHz.

Best Regards