The current EasyDMA implementation will fail if a transfer of over
255 bytes is requested with no warning.
Also we do not set the RX and TX transfer lengths to 0 if the
buffer is NULL which can cause data to be written to the old
address as well as cause unexpected transaction lenghts.
Example:
transfer 1:
rx_len = 10
rx_buff != NULL
tx_len = 10
tx_buff != NULL
transfer 2:
rx_len = 2
rx_buff != NULL
tx_buff == NULL
Total transaction length for the second would be 10 because it
would still be using the old rx length of 10 and would
corrupt data in the old rx buffer.
Signed-off-by: Brennan Ashton <bashton@brennanashton.com>
93eeecff6a