return 1;               /* we can serve this with scan logic */
 }
 
-static void interrupt_pci9118_ai_mode4_switch(struct comedi_device *dev)
+static void interrupt_pci9118_ai_mode4_switch(struct comedi_device *dev,
+                                             unsigned int next_buf)
 {
        struct pci9118_private *devpriv = dev->private;
-       struct pci9118_dmabuf *dmabuf;
-
-       dmabuf = &devpriv->dmabuf[1 - devpriv->dma_actbuf];
+       struct pci9118_dmabuf *dmabuf = &devpriv->dmabuf[next_buf];
 
        devpriv->ai_cfg = PCI9118_AI_CFG_PDTRG | PCI9118_AI_CFG_PETRG |
                          PCI9118_AI_CFG_AM;
                next_dma_buf = 1 - devpriv->dma_actbuf;
                pci9118_amcc_setup_dma(dev, next_dma_buf);
                if (devpriv->ai_do == 4)
-                       interrupt_pci9118_ai_mode4_switch(dev);
+                       interrupt_pci9118_ai_mode4_switch(dev, next_dma_buf);
        }
 
        if (samplesinbuf) {
                /* restart DMA if is not used double buffering */
                pci9118_amcc_setup_dma(dev, 0);
                if (devpriv->ai_do == 4)
-                       interrupt_pci9118_ai_mode4_switch(dev);
+                       interrupt_pci9118_ai_mode4_switch(dev, 0);
        }
 }