/* Request to transfer the entire buffer at once */
        bcount = min(pc->req_xfer, 63 * 1024);
 
-       if (drive->using_dma && !idescsi_map_sg(drive, pc)) {
+       if ((pc->flags & PC_FLAG_DMA_OK) && drive->using_dma) {
                hwif->sg_mapped = 1;
                dma = !hwif->dma_ops->dma_setup(drive);
                hwif->sg_mapped = 0;
        }
 
-       ide_pktcmd_tf_load(drive, 0, bcount, dma);
+       if (!dma)
+               pc->flags &= ~PC_FLAG_DMA_OK;
 
-       if (dma)
-               pc->flags |= PC_FLAG_DMA_OK;
+       ide_pktcmd_tf_load(drive, 0, bcount, dma);
 
        if (test_bit(IDESCSI_DRQ_INTERRUPT, &scsi->flags)) {
                ide_execute_command(drive, WIN_PACKETCMD, &idescsi_transfer_pc,
                  rq->sector, rq->nr_sectors, rq->current_nr_sectors);
 
        if (blk_sense_request(rq) || blk_special_request(rq)) {
-               return idescsi_issue_pc(drive,
-                               (struct ide_atapi_pc *) rq->special);
+               struct ide_atapi_pc *pc = (struct ide_atapi_pc *)rq->special;
+
+               if (drive->using_dma && !idescsi_map_sg(drive, pc))
+                       pc->flags |= PC_FLAG_DMA_OK;
+
+               return idescsi_issue_pc(drive, pc);
        }
        blk_dump_rq_flags(rq, "ide-scsi: unsup command");
        idescsi_end_request (drive, 0, 0);