diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index 650bc0a..e8cb505 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -29,7 +29,7 @@
 	if (pdev->is_pcie)
 		return NULL;
 	while (1) {
-		if (!pdev->bus->parent)
+		if (pci_is_root_bus(pdev->bus))
 			break;
 		pdev = pdev->bus->self;
 		/* a p2p bridge */