https://bugzilla.kernel.org/show_bug.cgi?id=94361 reported in ATCA platform, system had unusual pcie topology: (root port) (downstream port) (upstream port) +-1c.0-[02-0a]----00.0-[03-0a]--+-00.0-[04]-- | +-01.0-[05]-- (downstream port) | +-02.0-[06]-- | +-03.0-[07]-- | +-08.0-[08]-- | +-09.0-[09]-- | \-0a.0-[0a]-- We assumed root port and downstream port always have external link, and downstream port always has a upstream port. So in this case, when we allocated pcie_link_state for downstream port 02:00.0, it try to get parent bus pcie_link_state, parent = pdev->bus->parent->self->link_state; because root bus self is NULL, system will crash here. Use pdev->has_secondary_link(introduced in previous patch) to fix this issue. Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx> --- drivers/pci/pcie/aspm.c | 9 ++++----- 1 files changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 4e1af76..942bf97 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -525,7 +525,7 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev) INIT_LIST_HEAD(&link->children); INIT_LIST_HEAD(&link->link); link->pdev = pdev; - if (pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM) { + if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) { struct pcie_link_state *parent; parent = pdev->bus->parent->self->link_state; if (!parent) { @@ -561,8 +561,8 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) if (!pci_is_pcie(pdev) || pdev->link_state) return; - if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT && - pci_pcie_type(pdev) != PCI_EXP_TYPE_DOWNSTREAM) + + if (!pdev->has_secondary_link) return; /* VIA has a strange chipset, root port is under a bridge */ @@ -715,8 +715,7 @@ static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) if (!pci_is_pcie(pdev)) return; - if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT || - pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM) + if (pdev->has_secondary_link) parent = pdev; if (!parent || !parent->link_state) return; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
