MYRB_CMD_MBOX_COUNT
if (shost->can_queue > MYRB_CMD_MBOX_COUNT - 2)
shost->can_queue = MYRB_CMD_MBOX_COUNT - 2;
cb->cmd_mbox_size = MYRB_CMD_MBOX_COUNT * sizeof(union myrb_cmd_mbox);
cmd_mbox_mem += MYRB_CMD_MBOX_COUNT - 1;