linux-imx

         * When indirect descriptior is not supported, the I/O request

         * will be split between multiple request in the ring.

         * To avoid problems when sending the request, divide by

         * 2 the depth of the queue.

         */

        info->tag_set.queue_depth =  BLK_RING_SIZE(info) / 2;

    } else

        info->tag_set.queue_depth = BLK_RING_SIZE(info);

    info->tag_set.numa_node = NUMA_NO_NODE;

    info->tag_set.cmd_size = sizeof(struct blkif_req);

    info->tag_set.driver_data = info;

​

    if (blk_mq_alloc_tag_set(&info->tag_set))

        return -EINVAL;

    rq = blk_mq_init_queue(&info->tag_set);

    if (IS_ERR(rq)) {

        blk_mq_free_tag_set(&info->tag_set);

        return PTR_ERR(rq);

    }