return 0;
 }
 
-static void calc_block_sig(struct mlx5_cmd_prot_block *block, u8 token)
+static void calc_block_sig(struct mlx5_cmd_prot_block *block, u8 token,
+                          int csum)
 {
        block->token = token;
-       block->ctrl_sig = ~xor8_buf(block->rsvd0, sizeof(*block) - sizeof(block->data) - 2);
-       block->sig = ~xor8_buf(block, sizeof(*block) - 1);
+       if (csum) {
+               block->ctrl_sig = ~xor8_buf(block->rsvd0, sizeof(*block) -
+                                           sizeof(block->data) - 2);
+               block->sig = ~xor8_buf(block, sizeof(*block) - 1);
+       }
 }
 
-static void calc_chain_sig(struct mlx5_cmd_msg *msg, u8 token)
+static void calc_chain_sig(struct mlx5_cmd_msg *msg, u8 token, int csum)
 {
        struct mlx5_cmd_mailbox *next = msg->next;
 
        while (next) {
-               calc_block_sig(next->buf, token);
+               calc_block_sig(next->buf, token, csum);
                next = next->next;
        }
 }
 
-static void set_signature(struct mlx5_cmd_work_ent *ent)
+static void set_signature(struct mlx5_cmd_work_ent *ent, int csum)
 {
        ent->lay->sig = ~xor8_buf(ent->lay, sizeof(*ent->lay));
-       calc_chain_sig(ent->in, ent->token);
-       calc_chain_sig(ent->out, ent->token);
+       calc_chain_sig(ent->in, ent->token, csum);
+       calc_chain_sig(ent->out, ent->token, csum);
 }
 
 static void poll_timeout(struct mlx5_cmd_work_ent *ent)
        lay->type = MLX5_PCI_CMD_XPORT;
        lay->token = ent->token;
        lay->status_own = CMD_OWNER_HW;
-       if (!cmd->checksum_disabled)
-               set_signature(ent);
+       set_signature(ent, !cmd->checksum_disabled);
        dump_command(dev, ent, 1);
        ktime_get_ts(&ent->ts1);
 
 
                copy = min_t(int, size, MLX5_CMD_DATA_BLOCK_SIZE);
                block = next->buf;
-               if (xor8_buf(block, sizeof(*block)) != 0xff)
-                       return -EINVAL;
 
                memcpy(to, block->data, copy);
                to += copy;
                goto err_map;
        }
 
+       cmd->checksum_disabled = 1;
        cmd->max_reg_cmds = (1 << cmd->log_sz) - 1;
        cmd->bitmask = (1 << cmd->max_reg_cmds) - 1;
 
 
        struct mlx5_cmd_set_hca_cap_mbox_in *set_ctx = NULL;
        struct mlx5_cmd_query_hca_cap_mbox_in query_ctx;
        struct mlx5_cmd_set_hca_cap_mbox_out set_out;
-       struct mlx5_profile *prof = dev->profile;
        u64 flags;
-       int csum = 1;
        int err;
 
        memset(&query_ctx, 0, sizeof(query_ctx));
        memcpy(&set_ctx->hca_cap, &query_out->hca_cap,
               sizeof(set_ctx->hca_cap));
 
-       if (prof->mask & MLX5_PROF_MASK_CMDIF_CSUM) {
-               csum = !!prof->cmdif_csum;
-               flags = be64_to_cpu(set_ctx->hca_cap.flags);
-               if (csum)
-                       flags |= MLX5_DEV_CAP_FLAG_CMDIF_CSUM;
-               else
-                       flags &= ~MLX5_DEV_CAP_FLAG_CMDIF_CSUM;
-
-               set_ctx->hca_cap.flags = cpu_to_be64(flags);
-       }
-
        if (dev->profile->mask & MLX5_PROF_MASK_QP_SIZE)
                set_ctx->hca_cap.log_max_qp = dev->profile->log_max_qp;
 
+       flags = be64_to_cpu(query_out->hca_cap.flags);
+       /* disable checksum */
+       flags &= ~MLX5_DEV_CAP_FLAG_CMDIF_CSUM;
+
+       set_ctx->hca_cap.flags = cpu_to_be64(flags);
        memset(&set_out, 0, sizeof(set_out));
        set_ctx->hca_cap.log_uar_page_sz = cpu_to_be16(PAGE_SHIFT - 12);
        set_ctx->hdr.opcode = cpu_to_be16(MLX5_CMD_OP_SET_HCA_CAP);
        if (err)
                goto query_ex;
 
-       if (!csum)
-               dev->cmd.checksum_disabled = 1;
-
 query_ex:
        kfree(query_out);
        kfree(set_ctx);