sd_send_scsi_READ
rval = sd_send_scsi_READ(ssc, mode1->cdread_bufaddr,
rval = sd_send_scsi_READ(ssc, (dkl != NULL) ? dkl : bufaddr,
rval = sd_send_scsi_READ(ssc, dkl, buffer_size,
status = sd_send_scsi_READ(ssc, dkdevid, buffer_size, blk,