if (hwif->chipset != ide_dtc2278 || hwif->channel == 0)
                hwif->port_ops = d->port_ops;
 
-       if ((d->host_flags & IDE_HFLAG_SERIALIZE) && hwif->mate)
-               hwif->mate->serialized = hwif->serialized = 1;
+       if ((d->host_flags & IDE_HFLAG_SERIALIZE) ||
+           ((d->host_flags & IDE_HFLAG_SERIALIZE_DMA) && hwif->dma_base)) {
+               if (hwif->mate)
+                       hwif->mate->serialized = hwif->serialized = 1;
+       }
 
        hwif->swdma_mask = d->swdma_mask;
        hwif->mwdma_mask = d->mwdma_mask;
 
        hwif->dma_start                 = &sl82c105_dma_start;
        hwif->ide_dma_end               = &sl82c105_dma_end;
        hwif->dma_timeout               = &sl82c105_dma_timeout;
-
-       if (hwif->mate)
-               hwif->serialized = hwif->mate->serialized = 1;
 }
 
 static const struct ide_port_ops sl82c105_port_ops = {
 #if defined(CONFIG_LOPEC) || defined(CONFIG_SANDPOINT)
                          IDE_HFLAG_FORCE_LEGACY_IRQS |
 #endif
+                         IDE_HFLAG_SERIALIZE_DMA |
                          IDE_HFLAG_NO_AUTODMA,
        .pio_mask       = ATA_PIO5,
        .mwdma_mask     = ATA_MWDMA2,
                                 "revision %d, BM-DMA disabled\n", rev);
                d.init_hwif = NULL;
                d.mwdma_mask = 0;
+               d.host_flags &= ~IDE_HFLAG_SERIALIZE_DMA;
        }
 
        return ide_setup_pci_device(dev, &d);
 
        /* unmask IRQs */
        IDE_HFLAG_UNMASK_IRQS           = (1 << 25),
        IDE_HFLAG_ABUSE_SET_DMA_MODE    = (1 << 26),
+       /* serialize ports if DMA is possible (for sl82c105) */
+       IDE_HFLAG_SERIALIZE_DMA         = (1 << 27),
        /* force host out of "simplex" mode */
        IDE_HFLAG_CLEAR_SIMPLEX         = (1 << 28),
        /* DSC overlap is unsupported */