I am using i.MX6ULL, the kernel version is 4.1.15, DMA is enabled by default, and now I want to improve the performance of spi.
1. imx6ull starts to send data, after the cs pin pulls the bottom after 36us, the clk signal comes out.
2. After receiving the data, wait for 36us to pull up the cs pin.
3. Continuously send data, the two transf intervals are longer, about 160us.
I want to reduce these intervals, what should I do?