commit db4dabf552fd5f69f489118d9d1bf4480678b6cf
Author: Andy Grover <agrover@groveronline.com>
Date:   Thu Dec 5 00:43:35 2002 -0800

    ACPI: Never return a value from the PCI device's Interrupt Line field if
      it might be bogus -- return 0 instead.

diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index aca3df6..167b18c 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -346,9 +346,13 @@ acpi_pci_irq_enable (
 	 */
 	if (!irq) {
 		printk(KERN_WARNING PREFIX "No IRQ known for interrupt pin %c of device %s", ('A' + pin), dev->slot_name);
-		if (dev->irq) 
+		/* Interrupt Line values above 0xF are forbidden */
+		if (dev->irq && dev->irq >= 0xF) {
 			printk(" - using IRQ %d\n", dev->irq);
-		return_VALUE(dev->irq);
+			return_VALUE(dev->irq);
+		}
+		else
+			return_VALUE(0);
  	}
 
 	dev->irq = irq;