Acquiring Data via McSPI on AM/DM3703 with Linux

Hello,

 I have 2 questions regarding (1) The optimum number of bytes that can be acquired via SPI interface on Linux. (2) The rate at which data can be acquired over SPI. I'll give an idea about what I'm working on now so that the above points could be clearer :

(1) The DM3703 processor interfaces with a uController r via SPI interface with the DM3703 processor being the SPI bus master and the uController as the SPI bus slave. The data packets could be exchanged at a rate of 102, 510, and 1020 Hz from the uController.

(2) The packet size to be exchanged is 30 Bytes [checksum included].

(3) At a rate of 102 Hz, all packets are received without any errors. The SPI bus speed can go up to 6 MHz without any errors, however, I just left it at 3 MHz.

(4) At a rate of 510 Hz, I receive some packets with checksum errors. I can receive up to 4 wrong packets each second.

(5) At a rate of 1020 Hz, I receive more packets with checksum errors and some packets are not even received at all. I can know that because each packet has a sequence number.

(6) I used the UART interface previously on these Sitara processors to receive similar data packets at a rate of 1020 Hz and I didn't receive one packet with errors.

So it seems that I'm missing something when it comes to SPI interfacing on the Sitara processors using linux.

Thanks,

-- Walid F. Abdelfatah