diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index a1d582e38627..29c2160bcbb5 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -2046,6 +2046,7 @@ static void __init fixup_device_tree_maple(void)
 /*
  * Pegasos and BriQ lacks the "ranges" property in the isa node
  * Pegasos needs decimal IRQ 14/15, not hexadecimal
+ * Pegasos has the IDE configured in legacy mode, but advertised as native
  */
 static void __init fixup_device_tree_chrp(void)
 {
@@ -2083,9 +2084,13 @@ static void __init fixup_device_tree_chrp(void)
 		prom_printf("Fixing up IDE interrupt on Pegasos...\n");
 		prop[0] = 14;
 		prop[1] = 0x0;
-		prop[2] = 15;
-		prop[3] = 0x0;
-		prom_setprop(ph, name, "interrupts", prop, 4*sizeof(u32));
+		prom_setprop(ph, name, "interrupts", prop, 2*sizeof(u32));
+		prom_printf("Fixing up IDE class-code on Pegasos...\n");
+		rc = prom_getprop(ph, "class-code", prop, sizeof(u32));
+		if (rc == sizeof(u32)) {
+			prop[0] &= ~0x5;
+			prom_setprop(ph, name, "class-code", prop, sizeof(u32));
+		}
 	}
 }
 #else
diff --git a/arch/powerpc/platforms/chrp/pci.c b/arch/powerpc/platforms/chrp/pci.c
index 0c6dba9823e9..974952ed15cb 100644
--- a/arch/powerpc/platforms/chrp/pci.c
+++ b/arch/powerpc/platforms/chrp/pci.c
@@ -338,3 +338,32 @@ void chrp_pci_fixup_winbond_ata(struct pci_dev *sl82c105)
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_82C105,
 		chrp_pci_fixup_winbond_ata);
+
+/* Pegasos2 firmware version 20040810 configures the built-in IDE controller
+ * in legacy mode, but sets the PCI registers to PCI native mode.
+ * The chip can only operate in legacy mode, so force the PCI class into legacy
+ * mode as well. The same fixup must be done to the class-code property in
+ * the IDE node /pci@80000000/ide@C,1
+ */
+static void chrp_pci_fixup_vt8231_ata(struct pci_dev *viaide)
+{
+	u8 progif;
+	struct pci_dev *viaisa;
+
+	if (!machine_is(chrp) || _chrp_type != _CHRP_Pegasos)
+		return;
+	if (viaide->irq != 14)
+		return;
+
+	viaisa = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231, NULL);
+	if (!viaisa)
+		return;
+	printk("Fixing VIA IDE, force legacy mode on '%s'\n", viaide->dev.bus_id);
+
+	pci_read_config_byte(viaide, PCI_CLASS_PROG, &progif);
+	pci_write_config_byte(viaide, PCI_CLASS_PROG, progif & ~0x5);
+	viaide->class &= ~0x5;
+
+	pci_dev_put(viaisa);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_1, chrp_pci_fixup_vt8231_ata);