When the kernel is being initialized, and some hardwares are not added to system, there won't be acpi_device structs for these devices. But acpi_is_root_bridge() depends on acpi_device struct. As a result, all the not-added root bridge will not be judged as a root bridge in find_root_bridges(). And further more, no handle_hotplug_event_root() notifier will be installed for them. This patch introduces a new api to find all root bridges in system by getting HID directly from ACPI namespace, not depending on acpi_device struct. Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx> Signed-off-by: Liu Jiang <jiang.liu@xxxxxxxxxx> --- drivers/acpi/pci_root.c | 19 +++++++++++-------- 1 files changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 6151d83..582eb11 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -129,20 +129,23 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle); * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge * @handle - the ACPI CA node in question. * - * Note: we could make this API take a struct acpi_device * instead, but - * for now, it's more convenient to operate on an acpi_handle. + * Note: If a device is not added to the system yet, there won't be an + * acpi_device struct for it. So do not get HID and CID from acpi_device, + * get them from ACPI namespace directly. */ int acpi_is_root_bridge(acpi_handle handle) { - int ret; - struct acpi_device *device; + struct acpi_device_info *info; + acpi_status status; - ret = acpi_bus_get_device(handle, &device); - if (ret) + status = acpi_get_object_info(handle, &info); + if (ACPI_FAILURE(status)) { + printk(KERN_ERR PREFIX "%s: Error reading" + "device info\n", __func__); return 0; + } - ret = acpi_match_device_ids(device, root_device_ids); - if (ret) + if (acpi_match_object_info_ids(info, root_device_ids)) return 0; else return 1; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html