From: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>

pci_scan_slot() returns number of new devices connected *directly*
connected to the slot. Current enable_device() checks the return value
and stops if it doesn't see a new device.

In Thunderbolt chaining case the new device can be deeper in hierarchy, so
do the rescan anyway.

Because of that we must make sure that pcibios_resource_survey_bus() and
check_hotplug_bridge() get called only for a just found bus and not the
ones already added to the system. Failure to do so will lead to resource
conflicts.

Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerb...@linux.intel.com>
---
 drivers/pci/hotplug/acpiphp_glue.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/hotplug/acpiphp_glue.c 
b/drivers/pci/hotplug/acpiphp_glue.c
index b983e29..80a6ea1 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -685,18 +685,13 @@ static int __ref enable_device(struct acpiphp_slot *slot)
        struct pci_dev *dev;
        struct pci_bus *bus = slot->bridge->pci_bus;
        struct acpiphp_func *func;
-       int num, max, pass;
+       int max, pass;
        LIST_HEAD(add_list);
 
        list_for_each_entry(func, &slot->funcs, sibling)
                acpiphp_bus_add(func);
 
-       num = pci_scan_slot(bus, PCI_DEVFN(slot->device, 0));
-       if (num == 0) {
-               /* Maybe only part of funcs are added. */
-               dbg("No new device found\n");
-               goto err_exit;
-       }
+       pci_scan_slot(bus, PCI_DEVFN(slot->device, 0));
 
        max = acpiphp_max_busnr(bus);
        for (pass = 0; pass < 2; pass++) {
@@ -707,8 +702,11 @@ static int __ref enable_device(struct acpiphp_slot *slot)
                            dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
                                max = pci_scan_bridge(bus, dev, max, pass);
                                if (pass && dev->subordinate) {
-                                       check_hotplug_bridge(slot, dev);
-                                       
pcibios_resource_survey_bus(dev->subordinate);
+                                       if (!dev->subordinate->is_added) {
+                                               check_hotplug_bridge(slot, dev);
+                                               pcibios_resource_survey_bus(
+                                                       dev->subordinate);
+                                       }
                                        __pci_bus_size_bridges(dev->subordinate,
                                                               &add_list);
                                }
@@ -742,8 +740,6 @@ static int __ref enable_device(struct acpiphp_slot *slot)
                }
        }
 
-
- err_exit:
        return 0;
 }
 
-- 
1.8.3.1

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