dvc_var.adv_dvc_var)
 #define adv_dvc_to_pdev(adv_dvc) to_pci_dev(adv_dvc_to_board(adv_dvc)->dev)
 
+struct advansys_cmd {
+       dma_addr_t dma_handle;
+};
+
+static struct advansys_cmd *advansys_cmd(struct scsi_cmnd *cmd)
+{
+       return scsi_cmd_priv(cmd);
+}
+
 #ifdef ADVANSYS_DEBUG
 static int asc_dbglvl = 3;
 
 
        ASC_STATS(boardp->shost, callback);
 
-       dma_unmap_single(boardp->dev, scp->SCp.dma_handle,
+       dma_unmap_single(boardp->dev, advansys_cmd(scp)->dma_handle,
                         SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
        /*
         * 'qdonep' contains the command's ending status.
 static __le32 asc_get_sense_buffer_dma(struct scsi_cmnd *scp)
 {
        struct asc_board *board = shost_priv(scp->device->host);
+       struct advansys_cmd *acmd = advansys_cmd(scp);
 
-       scp->SCp.dma_handle = dma_map_single(board->dev, scp->sense_buffer,
-                                            SCSI_SENSE_BUFFERSIZE,
-                                            DMA_FROM_DEVICE);
-       if (dma_mapping_error(board->dev, scp->SCp.dma_handle)) {
+       acmd->dma_handle = dma_map_single(board->dev, scp->sense_buffer,
+                                       SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+       if (dma_mapping_error(board->dev, acmd->dma_handle)) {
                ASC_DBG(1, "failed to map sense buffer\n");
                return 0;
        }
-       return cpu_to_le32(scp->SCp.dma_handle);
+       return cpu_to_le32(acmd->dma_handle);
 }
 
 static int asc_build_req(struct asc_board *boardp, struct scsi_cmnd *scp,
        .eh_host_reset_handler = advansys_reset,
        .bios_param = advansys_biosparam,
        .slave_configure = advansys_slave_configure,
+       .cmd_size = sizeof(struct advansys_cmd),
 };
 
 static int advansys_wide_init_chip(struct Scsi_Host *shost)