If ACPI doesn't find an irq listed, don't accept 0 as a valid PCI irq.

That zero just means that nothing else found any irq information either.

drivers/acpi/pci_irq.c

@@ -433,7 +433,7 @@ acpi_pci_irq_enable (
 		printk(KERN_WARNING PREFIX "PCI Interrupt %s[%c]: no GSI",
 			pci_name(dev), ('A' + pin));
 		/* Interrupt Line values above 0xF are forbidden */
-		if (dev->irq >= 0 && (dev->irq <= 0xF)) {
+		if (dev->irq > 0 && (dev->irq <= 0xF)) {
 			printk(" - using IRQ %d\n", dev->irq);
 			acpi_register_gsi(dev->irq, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_LOW);
 			return_VALUE(0);