Hi,
I are using mcspi module with TI816x. In omap2_mcspi.c,
" /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
* cache operations; better heuristics consider wordsize and bitrate.
*/
#if defined(CONFIG_ARCH_TI816X) /* TI816x works only in PIO */
#define DMA_MIN_BYTES (4 * 1024 * 1024)
#else
#define DMA_MIN_BYTES 8
#endif ",
it says that TI816x works only in PIO.
Why TI816x can't use DMA MODE? As long as data length is less DMA_MIN_BYTES(4 * 1024 * 1024), then only PIO is used ???
PIO should be used for small transfer, then such as 2*1024*1024 bytes are small transfer ???
Thanks,
Golden
