diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 0f40943a9a18a6302c4fc8079ac391f5223dbe1a..260a06fb78a6132b27ba839b082625e4c2e44e9f 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -1249,6 +1249,9 @@ static struct acpi_device *acpi_pci_find_companion(struct device *dev)
 	bool check_children;
 	u64 addr;
 
+	if (!dev->parent)
+		return NULL;
+
 	down_read(&pci_acpi_companion_lookup_sem);
 
 	adev = pci_acpi_find_companion_hook ?