Proper way to flush cache when using SPI DMA?

I'm using an ADSP-SC573.

What is the proper way to flush the memory cache when using SPI DMA (in ARM core)?

I have a txBuffer[] array that contains the data I want to send on the SPI. And I have an rxBuffer[] array that will collect all received data from SPI.

I have setup the SPI and DMA using register level coding.

The problem I have is that the rxBuffer[] only gets updated once. I suspect it is a cache problem.

Is this the proper way?

1. Update txBuffer[] with new data to be sent on SPI
2. Call flush_data_buffer() så DMA will read the new data from txBuffer[]
3. Setup SPI as master transmitter/receiver and DMA to send txBuffer[] and receive data to rxBuffer[]
4. Call flush_data_buffer()  so CPU can see the new data in rxBuffer.

It didn't work, rxBuffer[] is only updated once I suspect I must call flush_data_buffer() with another argument. I will try it tomorrow.

Any tips?

**Update**

I got Rx and Tx to work today by doing this:

1. Update txBuffer[] with new data to be sent on SPI
2. Call flush_data_buffer((void *)pFlushStartaddr, (void *)pFlushEndaddr, ADI_FLUSH_DATA_NOINV) så DMA will read the new data from txBuffer[]
3. Setup SPI as master transmitter/receiver and DMA to send txBuffer[] and receive data to rxBuffer[]
4. Call flush_data_buffer(*pREG_DMA27_ADDRSTART, (void *)((uint32_t)*pREG_DMA27_ADDR_CUR - 1), ADI_FLUSH_DATA_INV);  so CPU can see the new data in rxBuffer.

So before sending data i called flush_data_buffer() with ADI_FLUSH_DATA_NOINV. And after receiving the SPI data I called flush_data_buffer() with ADI_FLUSH_DATA_INV.

What is the technical difference between ADI_FLUSH_DATA_NOINV and ADI_FLUSH_DATA_INV?

And is this the correct way to do this?