I have a a custom iMX6q board which have an FPGA connected on the EIM bus. It's work well while I get data from fpga using ioread16(). I want to transfort data using dma, so i download the mxc_sdma_memcopy_test.c and mxc_sdma_test.c. The driver and app is ok. However, while i replace the wbuf using the fpga address, it make no sense. I can't see any pulse on the eim bus. what is wrong with it?