DMAC_BUFFER_SIZE
length = min_t(unsigned int, host->scsi.SCp.this_residual, DMAC_BUFFER_SIZE / 2);
(DMAC_BUFFER_SIZE - 1);
length = min_t(unsigned int, host->scsi.SCp.this_residual, DMAC_BUFFER_SIZE / 2);
(DMAC_BUFFER_SIZE - 1);