I want to use DMA copy data from external memory to internal memory in Linux 3.0.35/Linux 4.1.15 and I.MX6Q board.
I haved config DISP0_DAT17 for sdma_ext_event(It is invalid when I config GPIO18).
Now I encounter some problems.
After i config dma, i trigger dma with a pulse. From the values that I read from EP and DMA Requests register I can know that DMA request has been received.But I can not receive callback.When i stop trigger dma, the value i read from EP register remains unchanged.I think it means DMA is not done.So, How can it be done if the read fifo has been full?