ACPI / hotplug / PCI: Runtime resume bridge before rescan

If a PCI bridge (or PCIe port) that is runtime suspended gets an ACPI
hotplug event, such as BUS_CHECK we need to make sure it is resumed before
devices below the bridge are re-scanned. Otherwise the devices behind the
port are not accessible and will be treated as hot-unplugged.

To fix this, resume PCI bridges from runtime suspend while rescanning.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index fa49f91..6a33ddc 100644 (file)
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -675,6 +675,8 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
        if (bridge->is_going_away)
                return;
 
+       pm_runtime_get_sync(&bridge->pci_dev->dev);
+
        list_for_each_entry(slot, &bridge->slots, node) {
                struct pci_bus *bus = slot->bus;
                struct pci_dev *dev, *tmp;
@@ -694,6 +696,8 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
                        disable_slot(slot);
                }
        }
+
+       pm_runtime_put(&bridge->pci_dev->dev);
 }
 
 /*