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PCI hotplug: fix wrong assumption in acpi_get_hp_hw_control_from_firmware 

Current acpi_get_hp_hw_control_from_firmware() has a assumption that
pci_bus->self is NULL on a PCI root bus. But it might not be true on
some platforms. Because of this wrong assumption, current
acpi_get_hp_hw_control_from_firmware() might cause endless loop. We
must check pci_bus->parent instead.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
Kenji Kaneshige 2009-02-17 14:13:59 +09:00 committed by Jesse Barnes
parent 267efd7eec
commit d391f00f0e
1 changed files with 12 additions and 22 deletions
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34
drivers/pci/hotplug/acpi_pcihp.c
View File

@ -372,12 +372,10 @@ EXPORT_SYMBOL_GPL(acpi_get_hp_params_from_firmware);
*
* Attempt to take hotplug control from firmware.
*/
int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
{
acpi_status status;
acpi_handle chandle, handle;
struct pci_dev *pdev = dev;
struct pci_bus *parent;
struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
flags &= (OSC_PCI_EXPRESS_NATIVE_HP_CONTROL |
@ -409,26 +407,18 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
string = (struct acpi_buffer){ ACPI_ALLOCATE_BUFFER, NULL };
}
pdev = dev;
handle = DEVICE_ACPI_HANDLE(&dev->dev);
while (!handle) {
handle = DEVICE_ACPI_HANDLE(&pdev->dev);
if (!handle) {
/*
* This hotplug controller was not listed in the ACPI name
* space at all. Try to get acpi handle of parent pci bus.
*/
if (!pdev || !pdev->bus->parent)
break;
parent = pdev->bus->parent;
dbg("Could not find %s in acpi namespace, trying parent\n",
pci_name(pdev));
if (!parent->self)
/* Parent must be a host bridge */
handle = acpi_get_pci_rootbridge_handle(
pci_domain_nr(parent),
parent->number);
else
handle = DEVICE_ACPI_HANDLE(&(parent->self->dev));
pdev = parent->self;
struct pci_bus *pbus;
for (pbus = pdev->bus; pbus; pbus = pbus->parent) {
handle = acpi_pci_get_bridge_handle(pbus);
if (handle)
break;
}
}
while (handle) {
@ -447,13 +437,13 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags)
}
dbg("Cannot get control of hotplug hardware for pci %s\n",
pci_name(dev));
pci_name(pdev));
kfree(string.pointer);
return -ENODEV;
got_one:
dbg("Gained control for hotplug HW for pci %s (%s)\n", pci_name(dev),
(char *)string.pointer);
dbg("Gained control for hotplug HW for pci %s (%s)\n",
pci_name(pdev), (char *)string.pointer);
kfree(string.pointer);
return 0;
}