case 2:
                devpriv->ai_ctrl |= PCI9118_AI_CTRL_TMRTR |
                                    PCI9118_AI_CTRL_DMA;
-               devpriv->ai_cfg = PCI9118_AI_CFG_PDTRG |
-                                 PCI9118_AI_CFG_PETRG |
-                                 PCI9118_AI_CFG_BM |
-                                 PCI9118_AI_CFG_BS;
+               devpriv->ai_cfg |= PCI9118_AI_CFG_BM |
+                                  PCI9118_AI_CFG_BS;
                if (cmd->convert_src == TRIG_NOW && !devpriv->softsshdelay)
                        devpriv->ai_cfg |= PCI9118_AI_CFG_BSSH;
                outl(devpriv->ai_n_realscanlen,
        case 3:
                devpriv->ai_ctrl |= PCI9118_AI_CTRL_EXTM |
                                    PCI9118_AI_CTRL_DMA;
-               devpriv->ai_cfg = PCI9118_AI_CFG_PDTRG |
-                                 PCI9118_AI_CFG_PETRG;
                break;
        case 4:
                devpriv->ai_ctrl |= PCI9118_AI_CTRL_TMRTR |
                                    PCI9118_AI_CTRL_DMA;
-               devpriv->ai_cfg = PCI9118_AI_CFG_PDTRG |
-                                 PCI9118_AI_CFG_PETRG |
-                                 PCI9118_AI_CFG_AM;
+               devpriv->ai_cfg |= PCI9118_AI_CFG_AM;
                outl(devpriv->ai_cfg, dev->iobase + PCI9118_AI_CFG_REG);
                pci9118_timer_set_mode(dev, 0, I8254_MODE0);
                pci9118_timer_write(dev, 0, dmabuf->hw >> 1);