writel(val, (void __iomem *) ap->ioaddr.scr_addr + (sc_reg * 4));
 }
 
-static void pdc_atapi_dma_pkt(struct ata_queued_cmd *qc)
+static void pdc_atapi_pkt(struct ata_queued_cmd *qc)
 {
        struct ata_port *ap = qc->ap;
        dma_addr_t sg_table = ap->prd_dma;
        /* set control bits (byte 0), zero delay seq id (byte 3),
         * and seq id (byte 2)
         */
-       if (!(qc->tf.flags & ATA_TFLAG_WRITE))
-               buf32[0] = cpu_to_le32(PDC_PKT_READ);
-       else
-               buf32[0] = 0;
+       switch (qc->tf.protocol) {
+       case ATA_PROT_ATAPI_DMA:
+               if (!(qc->tf.flags & ATA_TFLAG_WRITE))
+                       buf32[0] = cpu_to_le32(PDC_PKT_READ);
+               else
+                       buf32[0] = 0;
+               break;
+       case ATA_PROT_ATAPI_NODATA:
+               buf32[0] = cpu_to_le32(PDC_PKT_NODATA);
+               break;
+       default:
+               BUG();
+               break;
+       }
        buf32[1] = cpu_to_le32(sg_table);       /* S/G table addr */
        buf32[2] = 0;                           /* no next-packet */
 
                break;
 
        case ATA_PROT_ATAPI:
-       case ATA_PROT_ATAPI_NODATA:
                ata_qc_prep(qc);
                break;
 
        case ATA_PROT_ATAPI_DMA:
                ata_qc_prep(qc);
-               pdc_atapi_dma_pkt(qc);
+               /*FALLTHROUGH*/
+       case ATA_PROT_ATAPI_NODATA:
+               pdc_atapi_pkt(qc);
                break;
 
        default:
        case ATA_PROT_DMA:
        case ATA_PROT_NODATA:
        case ATA_PROT_ATAPI_DMA:
+       case ATA_PROT_ATAPI_NODATA:
                qc->err_mask |= ac_err_mask(ata_wait_idle(ap));
                ata_qc_complete(qc);
                handled = 1;
 static unsigned int pdc_qc_issue_prot(struct ata_queued_cmd *qc)
 {
        switch (qc->tf.protocol) {
+       case ATA_PROT_ATAPI_NODATA:
+               if (qc->dev->flags & ATA_DFLAG_CDB_INTR)
+                       break;
+               /*FALLTHROUGH*/
        case ATA_PROT_ATAPI_DMA:
        case ATA_PROT_DMA:
        case ATA_PROT_NODATA: