diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 4558f0d..97a874a 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -408,6 +408,9 @@ acpi_parse_int_src_ovr(struct acpi_subtable_header * header,
 
 	acpi_table_print_madt_entry(header);
 
+	printk(KERN_INFO "source_irq is %d, global is %d and FADT is %d\n",
+			intsrc->source_irq, intsrc->global_irq, acpi_gbl_FADT.sci_interrupt);
+
 	if (intsrc->source_irq == acpi_gbl_FADT.sci_interrupt) {
 		acpi_sci_ioapic_setup(intsrc->source_irq,
 				      intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 8214724..10fa094 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -353,7 +353,7 @@ static int xen_register_pirq(u32 gsi, int triggering)
 	if (irq < 0)
 		goto out;
 
-	printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d\n", pirq, irq);
+	printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (%s)\n", pirq, irq, name);
 
 	map_irq.domid = DOMID_SELF;
 	map_irq.type = MAP_PIRQ_TYPE_GSI;
@@ -404,8 +404,8 @@ static __init void xen_setup_acpi_sci(void)
 	int trigger, polarity;
 	int gsi = acpi_sci_override_gsi;
 
-	if (!gsi)
-		return;
+	/* Can ACPI SCI be zero!? */
+	WARN_ON(!gsi);
 
 	rc = acpi_get_override_irq(gsi, &trigger, &polarity);
 	if (rc) {
@@ -413,6 +413,9 @@ static __init void xen_setup_acpi_sci(void)
 				" sci, rc=%d\n", rc);
 		return;
 	}
+	printk(KERN_INFO "xen: sci %d before sanitize %d %d\n", gsi,
+			trigger, polarity);
+
 	trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
 	polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
 	
@@ -457,15 +460,18 @@ void __init xen_setup_pirqs(void)
 				break;
 			irq = xen_bind_pirq_gsi_to_irq(irq, pirq, 0, "xt-pic");
 		}
-		return;
 	}
 
 	/* Pre-allocate legacy irqs */
 	for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
 		int trigger, polarity;
 
-		if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
+		if (acpi_get_override_irq(irq, &trigger, &polarity) == -1) {
+			printk(KERN_INFO "IRQ %s - unknown.\n", irq);
 			continue;
+		}
+		printk(KERN_INFO "IRQ %d is %s %s\n", irq, polarity == ACPI_ACTIVE_LOW ? "low" :"high",
+			trigger == ACPI_LEVEL_SENSITIVE ?"level" :"edge");
 
 		xen_register_pirq(irq,
 			trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE);