dma: caam: fix desc error when data length is over 130815 bytes

The CAAM DMA shared descriptor states that if a buffer is large enough it
is broken into chunks of maximum 65280 bytes (DMA_MAX_DATA_CHUNK) and for
each chunk a transfer request is issued. The length of the chunk for each
iteration should be therefore computed as min(DMA_MAX_DATA_CHUNK,
data_rem_length), where data_rem_length is the length of the chunks that
still remain to be send.

Currently the logic of the shared descriptor is broken: on every iteration
the chunk length is instead computed as max(max_chunk_size,
data_rem_length). This produces an error for the first chunk when buffer
data length is greater than max_chunk_size + max_allowed_chunk_size =
65280 + 65535 = 130815.

Signed-off-by: Radu Alexe <radu.alexe@nxp.com>

0 files changed, 0 insertions, 0 deletions