Merge tag 'pci-v4.10-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fix from Bjorn Helgaas:
 "Configure ASPM on the link from a PCI-to-PCIe bridge (avoids a NULL
  pointer dereference on topologies including these bridges)"

* tag 'pci-v4.10-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI/ASPM: Handle PCI-to-PCIe bridges as roots of PCIe hierarchies

1 files changed, 13 insertions, 6 deletions

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 17ac1dce3286..3dd8bcbb3011 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -532,25 +532,32 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev)
 	link = kzalloc(sizeof(*link), GFP_KERNEL);
 	if (!link)
 		return NULL;
+
 	INIT_LIST_HEAD(&link->sibling);
 	INIT_LIST_HEAD(&link->children);
 	INIT_LIST_HEAD(&link->link);
 	link->pdev = pdev;
-	if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) {
+
+	/*
+	 * Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe
+	 * hierarchies.
+	 */
+	if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
+	    pci_pcie_type(pdev) == PCI_EXP_TYPE_PCIE_BRIDGE) {
+		link->root = link;
+	} else {
 		struct pcie_link_state *parent;
+
 		parent = pdev->bus->parent->self->link_state;
 		if (!parent) {
 			kfree(link);
 			return NULL;
 		}
+
 		link->parent = parent;
+		link->root = link->parent->root;
 		list_add(&link->link, &parent->children);
 	}
-	/* Setup a pointer to the root port link */
-	if (!link->parent)
-		link->root = link;
-	else
-		link->root = link->parent->root;
 
 	list_add(&link->sibling, &link_list);
 	pdev->link_state = link;