diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 1dfa10cc566bebed005c2fe11a72c85a37036c32..0bea8498b5a5b470087d692e5fddb6d218c532d8 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -802,10 +802,14 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev)
 
 	/*
 	 * Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe
-	 * hierarchies.
+	 * hierarchies.  Note that some PCIe host implementations omit
+	 * the root ports entirely, in which case a downstream port on
+	 * a switch may become the root of the link state chain for all
+	 * its subordinate endpoints.
 	 */
 	if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
-	    pci_pcie_type(pdev) == PCI_EXP_TYPE_PCIE_BRIDGE) {
+	    pci_pcie_type(pdev) == PCI_EXP_TYPE_PCIE_BRIDGE ||
+	    !pdev->bus->parent->self) {
 		link->root = link;
 	} else {
 		struct pcie_link_state *parent;