--- linux-2.2.12/drivers/block/ide-pci.c.orig	Fri Nov  5 09:46:40 1999
+++ linux-2.2.12/drivers/block/ide-pci.c	Fri Nov  5 09:54:31 1999
@@ -24,6 +24,7 @@
 
 #include "ide.h"
 
+#define DEVID_450NX	((ide_pci_devid_t){PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_82451NX})
 #define DEVID_PIIXa	((ide_pci_devid_t){PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_82371FB_0})
 #define DEVID_PIIXb	((ide_pci_devid_t){PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_82371FB_1})
 #define DEVID_PIIX3	((ide_pci_devid_t){PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_82371SB_1})
@@ -285,16 +286,15 @@ __initfunc(static int ide_setup_pci_base
  * we "know" about, this information is in the ide_pci_device_t struct;
  * for all other chipsets, we just assume both interfaces are enabled.
  */
-__initfunc(static void ide_setup_pci_device (struct pci_dev *dev, ide_pci_device_t *d))
+__initfunc(static void ide_setup_pci_device (struct pci_dev *dev,
+					     ide_pci_device_t *d,
+					     int autodma))
 {
-	unsigned int port, at_least_one_hwif_enabled = 0, autodma = 0, pciirq = 0;
+	unsigned int port, at_least_one_hwif_enabled = 0, pciirq = 0;
 	unsigned short pcicmd = 0, tried_config = 0;
 	byte tmp = 0;
 	ide_hwif_t *hwif, *mate = NULL;
 
-#ifdef CONFIG_IDEDMA_AUTO
-	autodma = 1;
-#endif
 check_if_enabled:
 	if (pci_read_config_word(dev, PCI_COMMAND, &pcicmd)) {
 		printk("%s: error accessing PCI regs\n", d->name);
@@ -430,9 +430,25 @@ __initfunc(void ide_scan_pcibus (void))
 	struct pci_dev		*dev;
 	ide_pci_devid_t		devid;
 	ide_pci_device_t	*d;
+	int			autodma;
 
 	if (!pci_present())
 		return;
+
+#ifdef CONFIG_IDEDMA_AUTO
+	autodma = 1;
+	for(dev = pci_devices; dev; dev=dev->next) {
+		devid.vid = dev->vendor;
+		devid.did = dev->device;
+		if (IDE_PCI_DEVID_EQ(devid, DEVID_450NX)) {
+			autodma = 0;
+			break;
+		}
+	}
+#else
+	autodma = 0;
+#endif
+
 	for(dev = pci_devices; dev; dev=dev->next) {
 		devid.vid = dev->vendor;
 		devid.did = dev->device;
@@ -447,7 +463,7 @@ __initfunc(void ide_scan_pcibus (void))
 					d->name, dev->bus->number, dev->devfn, devid.vid, devid.did);
 			else
 				printk("%s: IDE controller on PCI bus %02x dev %02x\n", d->name, dev->bus->number, dev->devfn);
-			ide_setup_pci_device(dev, d);
+			ide_setup_pci_device(dev, d, autodma);
 		}
 	}
 }