diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 70b3b44..8ea911e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1549,7 +1549,7 @@
 {
 	u8 pin = *pinp;
 
-	while (dev->bus->parent) {
+	while (!pci_is_root_bus(dev->bus)) {
 		pin = pci_swizzle_interrupt_pin(dev, pin);
 		dev = dev->bus->self;
 	}