From 5ce79d201358d36f13d13b01d8614bd8e646036c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 28 Nov 2013 23:58:08 +0100 Subject: [PATCH] PCI / ACPI: Use acpi_find_child_device() for child devices lookup It is much more efficient to use acpi_find_child_device() for child devices lookup in acpi_pci_find_device() and pass ACPI_COMPANION(dev->parent) to it directly instead of obtaining ACPI_HANDLE() of ACPI_COMPANION(dev->parent) and passing it to acpi_find_child() which has to run acpi_bus_get_device() to obtain ACPI_COMPANION(dev->parent) from that again. Signed-off-by: Rafael J. Wysocki Reviewed-by: Aaron Lu --- drivers/acpi/glue.c | 3 +++ drivers/pci/pci-acpi.c | 16 ++++++++++------ 2 files changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c index ea77512..9d200d5 100644 --- a/drivers/acpi/glue.c +++ b/drivers/acpi/glue.c @@ -106,6 +106,9 @@ struct acpi_device *acpi_find_child_device(struct acpi_device *parent, struct acpi_device *adev, *ret = NULL; int ret_score = 0; + if (!parent) + return NULL; + list_for_each_entry(adev, &parent->children, node) { unsigned long long addr; acpi_status status; diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 43e3179..adbf340 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -306,7 +306,8 @@ void acpi_pci_remove_bus(struct pci_bus *bus) static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) { struct pci_dev *pci_dev = to_pci_dev(dev); - bool is_bridge; + struct acpi_device *adev; + bool check_children; u64 addr; /* @@ -314,14 +315,17 @@ static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) * is set only after acpi_pci_find_device() has been called for the * given device. */ - is_bridge = pci_dev->hdr_type == PCI_HEADER_TYPE_BRIDGE + check_children = pci_dev->hdr_type == PCI_HEADER_TYPE_BRIDGE || pci_dev->hdr_type == PCI_HEADER_TYPE_CARDBUS; /* Please ref to ACPI spec for the syntax of _ADR */ addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn); - *handle = acpi_find_child(ACPI_HANDLE(dev->parent), addr, is_bridge); - if (!*handle) - return -ENODEV; - return 0; + adev = acpi_find_child_device(ACPI_COMPANION(dev->parent), addr, + check_children); + if (adev) { + *handle = adev->handle; + return 0; + } + return -ENODEV; } static void pci_acpi_setup(struct device *dev) -- 2.7.4