PCI: disable ASPM on VIA root-port-under-bridge configurations

commit 8e822df700694ca6850d1e0c122fd7004b2778d8 upstream.

VIA has a strange chipset, it has root port under a bridge. Disable ASPM
for such strange chipset.

Tested-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index e4df84b3ba81bc85d64700651fab01b440cf5cf2..def3398d137421c91c01c5905344a826130a9b9f 100644 (file)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -633,6 +633,10 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
        if (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
                pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
                return;
+       /* VIA has a strange chipset, root port is under a bridge */
+       if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT &&
+               pdev->bus->self)
+               return;
        down_read(&pci_bus_sem);
        if (list_empty(&pdev->subordinate->devices))
                goto out;