From d391f00f0e7fb6d883c6724b31a1799e19a584c5 Mon Sep 17 00:00:00 2001 From: Kenji Kaneshige Date: Tue, 17 Feb 2009 14:13:59 +0900 Subject: [PATCH] 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 Signed-off-by: Jesse Barnes --- drivers/pci/hotplug/acpi_pcihp.c | 34 +++++++++++--------------------- 1 file changed, 12 insertions(+), 22 deletions(-) diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c index 09a84402986d..fbc63d5e459f 100644 --- a/drivers/pci/hotplug/acpi_pcihp.c +++ b/drivers/pci/hotplug/acpi_pcihp.c @@ -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; }