MAX_ASYNC_CMDS
async_cmd = kzalloc_objs(*async_cmd, MAX_ASYNC_CMDS);
async_cmd[tail % MAX_ASYNC_CMDS].in = obj->dinbox;
async_cmd[tail % MAX_ASYNC_CMDS].in_size = obj->dinlen;
async_cmd[tail % MAX_ASYNC_CMDS].uobject = uobject;
devx_async_destroy(dev, &async_cmd[tail % MAX_ASYNC_CMDS]);
if (tail - head == MAX_ASYNC_CMDS) {
devx_wait_async_destroy(&async_cmd[head % MAX_ASYNC_CMDS]);
devx_wait_async_destroy(&async_cmd[head % MAX_ASYNC_CMDS]);