linux/drivers/acpi/bus.c
Bjorn Helgaas e76f427611 ACPI: fix 2.6.28 acpi.debug_level regression
acpi_early_init() was changed to over-write the cmdline param,
making it really inconvenient to set debug flags at boot-time.

Also,
This sets the default level to "info", which is what all the ACPI
drivers use.  So to enable messages from drivers, you only have to
supply the "layer" (a.k.a. "component").  For non-"info" ACPI core
and ACPI interpreter messages, you have to supply both level and
layer masks, as before.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2008-12-19 04:38:32 -05:00

879 lines
22 KiB
C

/*
* acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
*
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/proc_fs.h>
#include <linux/acpi.h>
#ifdef CONFIG_X86
#include <asm/mpspec.h>
#endif
#include <linux/pci.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#define _COMPONENT ACPI_BUS_COMPONENT
ACPI_MODULE_NAME("bus");
struct acpi_device *acpi_root;
struct proc_dir_entry *acpi_root_dir;
EXPORT_SYMBOL(acpi_root_dir);
#define STRUCT_TO_INT(s) (*((int*)&s))
static int set_power_nocheck(const struct dmi_system_id *id)
{
printk(KERN_NOTICE PREFIX "%s detected - "
"disable power check in power transistion\n", id->ident);
acpi_power_nocheck = 1;
return 0;
}
static struct dmi_system_id __cpuinitdata power_nocheck_dmi_table[] = {
{
set_power_nocheck, "HP Pavilion 05", {
DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
DMI_MATCH(DMI_SYS_VENDOR, "HP Pavilion 05"),
DMI_MATCH(DMI_PRODUCT_VERSION, "2001211RE101GLEND") }, NULL},
{},
};
/* --------------------------------------------------------------------------
Device Management
-------------------------------------------------------------------------- */
int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
{
acpi_status status = AE_OK;
if (!device)
return -EINVAL;
/* TBD: Support fixed-feature devices */
status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
if (ACPI_FAILURE(status) || !*device) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
handle));
return -ENODEV;
}
return 0;
}
EXPORT_SYMBOL(acpi_bus_get_device);
int acpi_bus_get_status(struct acpi_device *device)
{
acpi_status status = AE_OK;
unsigned long long sta = 0;
if (!device)
return -EINVAL;
/*
* Evaluate _STA if present.
*/
if (device->flags.dynamic_status) {
status =
acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status))
return -ENODEV;
STRUCT_TO_INT(device->status) = (int)sta;
}
/*
* According to ACPI spec some device can be present and functional
* even if the parent is not present but functional.
* In such conditions the child device should not inherit the status
* from the parent.
*/
else
STRUCT_TO_INT(device->status) =
ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
ACPI_STA_DEVICE_UI | ACPI_STA_DEVICE_FUNCTIONING;
if (device->status.functional && !device->status.present) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
"functional but not present;\n",
device->pnp.bus_id,
(u32) STRUCT_TO_INT(device->status)));
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
device->pnp.bus_id,
(u32) STRUCT_TO_INT(device->status)));
return 0;
}
EXPORT_SYMBOL(acpi_bus_get_status);
void acpi_bus_private_data_handler(acpi_handle handle,
u32 function, void *context)
{
return;
}
EXPORT_SYMBOL(acpi_bus_private_data_handler);
int acpi_bus_get_private_data(acpi_handle handle, void **data)
{
acpi_status status = AE_OK;
if (!*data)
return -EINVAL;
status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
if (ACPI_FAILURE(status) || !*data) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
handle));
return -ENODEV;
}
return 0;
}
EXPORT_SYMBOL(acpi_bus_get_private_data);
/* --------------------------------------------------------------------------
Power Management
-------------------------------------------------------------------------- */
int acpi_bus_get_power(acpi_handle handle, int *state)
{
int result = 0;
acpi_status status = 0;
struct acpi_device *device = NULL;
unsigned long long psc = 0;
result = acpi_bus_get_device(handle, &device);
if (result)
return result;
*state = ACPI_STATE_UNKNOWN;
if (!device->flags.power_manageable) {
/* TBD: Non-recursive algorithm for walking up hierarchy */
if (device->parent)
*state = device->parent->power.state;
else
*state = ACPI_STATE_D0;
} else {
/*
* Get the device's power state either directly (via _PSC) or
* indirectly (via power resources).
*/
if (device->power.flags.explicit_get) {
status = acpi_evaluate_integer(device->handle, "_PSC",
NULL, &psc);
if (ACPI_FAILURE(status))
return -ENODEV;
device->power.state = (int)psc;
} else if (device->power.flags.power_resources) {
result = acpi_power_get_inferred_state(device);
if (result)
return result;
}
*state = device->power.state;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
device->pnp.bus_id, device->power.state));
return 0;
}
EXPORT_SYMBOL(acpi_bus_get_power);
int acpi_bus_set_power(acpi_handle handle, int state)
{
int result = 0;
acpi_status status = AE_OK;
struct acpi_device *device = NULL;
char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
result = acpi_bus_get_device(handle, &device);
if (result)
return result;
if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
return -EINVAL;
/* Make sure this is a valid target state */
if (!device->flags.power_manageable) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n",
kobject_name(&device->dev.kobj)));
return -ENODEV;
}
/*
* Get device's current power state
*/
if (!acpi_power_nocheck) {
/*
* Maybe the incorrect power state is returned on the bogus
* bios, which is different with the real power state.
* For example: the bios returns D0 state and the real power
* state is D3. OS expects to set the device to D0 state. In
* such case if OS uses the power state returned by the BIOS,
* the device can't be transisted to the correct power state.
* So if the acpi_power_nocheck is set, it is unnecessary to
* get the power state by calling acpi_bus_get_power.
*/
acpi_bus_get_power(device->handle, &device->power.state);
}
if ((state == device->power.state) && !device->flags.force_power_state) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
state));
return 0;
}
if (!device->power.states[state].flags.valid) {
printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
return -ENODEV;
}
if (device->parent && (state < device->parent->power.state)) {
printk(KERN_WARNING PREFIX
"Cannot set device to a higher-powered"
" state than parent\n");
return -ENODEV;
}
/*
* Transition Power
* ----------------
* On transitions to a high-powered state we first apply power (via
* power resources) then evalute _PSx. Conversly for transitions to
* a lower-powered state.
*/
if (state < device->power.state) {
if (device->power.flags.power_resources) {
result = acpi_power_transition(device, state);
if (result)
goto end;
}
if (device->power.states[state].flags.explicit_set) {
status = acpi_evaluate_object(device->handle,
object_name, NULL, NULL);
if (ACPI_FAILURE(status)) {
result = -ENODEV;
goto end;
}
}
} else {
if (device->power.states[state].flags.explicit_set) {
status = acpi_evaluate_object(device->handle,
object_name, NULL, NULL);
if (ACPI_FAILURE(status)) {
result = -ENODEV;
goto end;
}
}
if (device->power.flags.power_resources) {
result = acpi_power_transition(device, state);
if (result)
goto end;
}
}
end:
if (result)
printk(KERN_WARNING PREFIX
"Transitioning device [%s] to D%d\n",
device->pnp.bus_id, state);
else {
device->power.state = state;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Device [%s] transitioned to D%d\n",
device->pnp.bus_id, state));
}
return result;
}
EXPORT_SYMBOL(acpi_bus_set_power);
bool acpi_bus_power_manageable(acpi_handle handle)
{
struct acpi_device *device;
int result;
result = acpi_bus_get_device(handle, &device);
return result ? false : device->flags.power_manageable;
}
EXPORT_SYMBOL(acpi_bus_power_manageable);
bool acpi_bus_can_wakeup(acpi_handle handle)
{
struct acpi_device *device;
int result;
result = acpi_bus_get_device(handle, &device);
return result ? false : device->wakeup.flags.valid;
}
EXPORT_SYMBOL(acpi_bus_can_wakeup);
/* --------------------------------------------------------------------------
Event Management
-------------------------------------------------------------------------- */
#ifdef CONFIG_ACPI_PROC_EVENT
static DEFINE_SPINLOCK(acpi_bus_event_lock);
LIST_HEAD(acpi_bus_event_list);
DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
extern int event_is_open;
int acpi_bus_generate_proc_event4(const char *device_class, const char *bus_id, u8 type, int data)
{
struct acpi_bus_event *event;
unsigned long flags = 0;
/* drop event on the floor if no one's listening */
if (!event_is_open)
return 0;
event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
if (!event)
return -ENOMEM;
strcpy(event->device_class, device_class);
strcpy(event->bus_id, bus_id);
event->type = type;
event->data = data;
spin_lock_irqsave(&acpi_bus_event_lock, flags);
list_add_tail(&event->node, &acpi_bus_event_list);
spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
wake_up_interruptible(&acpi_bus_event_queue);
return 0;
}
EXPORT_SYMBOL_GPL(acpi_bus_generate_proc_event4);
int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data)
{
if (!device)
return -EINVAL;
return acpi_bus_generate_proc_event4(device->pnp.device_class,
device->pnp.bus_id, type, data);
}
EXPORT_SYMBOL(acpi_bus_generate_proc_event);
int acpi_bus_receive_event(struct acpi_bus_event *event)
{
unsigned long flags = 0;
struct acpi_bus_event *entry = NULL;
DECLARE_WAITQUEUE(wait, current);
if (!event)
return -EINVAL;
if (list_empty(&acpi_bus_event_list)) {
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&acpi_bus_event_queue, &wait);
if (list_empty(&acpi_bus_event_list))
schedule();
remove_wait_queue(&acpi_bus_event_queue, &wait);
set_current_state(TASK_RUNNING);
if (signal_pending(current))
return -ERESTARTSYS;
}
spin_lock_irqsave(&acpi_bus_event_lock, flags);
if (!list_empty(&acpi_bus_event_list)) {
entry = list_entry(acpi_bus_event_list.next,
struct acpi_bus_event, node);
list_del(&entry->node);
}
spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
if (!entry)
return -ENODEV;
memcpy(event, entry, sizeof(struct acpi_bus_event));
kfree(entry);
return 0;
}
#endif /* CONFIG_ACPI_PROC_EVENT */
/* --------------------------------------------------------------------------
Notification Handling
-------------------------------------------------------------------------- */
static int
acpi_bus_check_device(struct acpi_device *device, int *status_changed)
{
acpi_status status = 0;
struct acpi_device_status old_status;
if (!device)
return -EINVAL;
if (status_changed)
*status_changed = 0;
old_status = device->status;
/*
* Make sure this device's parent is present before we go about
* messing with the device.
*/
if (device->parent && !device->parent->status.present) {
device->status = device->parent->status;
if (STRUCT_TO_INT(old_status) != STRUCT_TO_INT(device->status)) {
if (status_changed)
*status_changed = 1;
}
return 0;
}
status = acpi_bus_get_status(device);
if (ACPI_FAILURE(status))
return -ENODEV;
if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
return 0;
if (status_changed)
*status_changed = 1;
/*
* Device Insertion/Removal
*/
if ((device->status.present) && !(old_status.present)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
/* TBD: Handle device insertion */
} else if (!(device->status.present) && (old_status.present)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
/* TBD: Handle device removal */
}
return 0;
}
static int acpi_bus_check_scope(struct acpi_device *device)
{
int result = 0;
int status_changed = 0;
if (!device)
return -EINVAL;
/* Status Change? */
result = acpi_bus_check_device(device, &status_changed);
if (result)
return result;
if (!status_changed)
return 0;
/*
* TBD: Enumerate child devices within this device's scope and
* run acpi_bus_check_device()'s on them.
*/
return 0;
}
static BLOCKING_NOTIFIER_HEAD(acpi_bus_notify_list);
int register_acpi_bus_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&acpi_bus_notify_list, nb);
}
EXPORT_SYMBOL_GPL(register_acpi_bus_notifier);
void unregister_acpi_bus_notifier(struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&acpi_bus_notify_list, nb);
}
EXPORT_SYMBOL_GPL(unregister_acpi_bus_notifier);
/**
* acpi_bus_notify
* ---------------
* Callback for all 'system-level' device notifications (values 0x00-0x7F).
*/
static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
{
int result = 0;
struct acpi_device *device = NULL;
blocking_notifier_call_chain(&acpi_bus_notify_list,
type, (void *)handle);
if (acpi_bus_get_device(handle, &device))
return;
switch (type) {
case ACPI_NOTIFY_BUS_CHECK:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Received BUS CHECK notification for device [%s]\n",
device->pnp.bus_id));
result = acpi_bus_check_scope(device);
/*
* TBD: We'll need to outsource certain events to non-ACPI
* drivers via the device manager (device.c).
*/
break;
case ACPI_NOTIFY_DEVICE_CHECK:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Received DEVICE CHECK notification for device [%s]\n",
device->pnp.bus_id));
result = acpi_bus_check_device(device, NULL);
/*
* TBD: We'll need to outsource certain events to non-ACPI
* drivers via the device manager (device.c).
*/
break;
case ACPI_NOTIFY_DEVICE_WAKE:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Received DEVICE WAKE notification for device [%s]\n",
device->pnp.bus_id));
/* TBD */
break;
case ACPI_NOTIFY_EJECT_REQUEST:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Received EJECT REQUEST notification for device [%s]\n",
device->pnp.bus_id));
/* TBD */
break;
case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Received DEVICE CHECK LIGHT notification for device [%s]\n",
device->pnp.bus_id));
/* TBD: Exactly what does 'light' mean? */
break;
case ACPI_NOTIFY_FREQUENCY_MISMATCH:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Received FREQUENCY MISMATCH notification for device [%s]\n",
device->pnp.bus_id));
/* TBD */
break;
case ACPI_NOTIFY_BUS_MODE_MISMATCH:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Received BUS MODE MISMATCH notification for device [%s]\n",
device->pnp.bus_id));
/* TBD */
break;
case ACPI_NOTIFY_POWER_FAULT:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Received POWER FAULT notification for device [%s]\n",
device->pnp.bus_id));
/* TBD */
break;
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Received unknown/unsupported notification [%08x]\n",
type));
break;
}
return;
}
/* --------------------------------------------------------------------------
Initialization/Cleanup
-------------------------------------------------------------------------- */
static int __init acpi_bus_init_irq(void)
{
acpi_status status = AE_OK;
union acpi_object arg = { ACPI_TYPE_INTEGER };
struct acpi_object_list arg_list = { 1, &arg };
char *message = NULL;
/*
* Let the system know what interrupt model we are using by
* evaluating the \_PIC object, if exists.
*/
switch (acpi_irq_model) {
case ACPI_IRQ_MODEL_PIC:
message = "PIC";
break;
case ACPI_IRQ_MODEL_IOAPIC:
message = "IOAPIC";
break;
case ACPI_IRQ_MODEL_IOSAPIC:
message = "IOSAPIC";
break;
case ACPI_IRQ_MODEL_PLATFORM:
message = "platform specific model";
break;
default:
printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
return -ENODEV;
}
printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
arg.integer.value = acpi_irq_model;
status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
return -ENODEV;
}
return 0;
}
u8 acpi_gbl_permanent_mmap;
void __init acpi_early_init(void)
{
acpi_status status = AE_OK;
if (acpi_disabled)
return;
printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
/* enable workarounds, unless strict ACPI spec. compliance */
if (!acpi_strict)
acpi_gbl_enable_interpreter_slack = TRUE;
acpi_gbl_permanent_mmap = 1;
status = acpi_reallocate_root_table();
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX
"Unable to reallocate ACPI tables\n");
goto error0;
}
status = acpi_initialize_subsystem();
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX
"Unable to initialize the ACPI Interpreter\n");
goto error0;
}
status = acpi_load_tables();
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX
"Unable to load the System Description Tables\n");
goto error0;
}
#ifdef CONFIG_X86
if (!acpi_ioapic) {
/* compatible (0) means level (3) */
if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
}
/* Set PIC-mode SCI trigger type */
acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
} else {
/*
* now that acpi_gbl_FADT is initialized,
* update it with result from INT_SRC_OVR parsing
*/
acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
}
#endif
status =
acpi_enable_subsystem(~
(ACPI_NO_HARDWARE_INIT |
ACPI_NO_ACPI_ENABLE));
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
goto error0;
}
return;
error0:
disable_acpi();
return;
}
static int __init acpi_bus_init(void)
{
int result = 0;
acpi_status status = AE_OK;
extern acpi_status acpi_os_initialize1(void);
status = acpi_os_initialize1();
status =
acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX
"Unable to start the ACPI Interpreter\n");
goto error1;
}
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX
"Unable to initialize ACPI OS objects\n");
goto error1;
}
/*
* ACPI 2.0 requires the EC driver to be loaded and work before
* the EC device is found in the namespace (i.e. before acpi_initialize_objects()
* is called).
*
* This is accomplished by looking for the ECDT table, and getting
* the EC parameters out of that.
*/
status = acpi_ec_ecdt_probe();
/* Ignore result. Not having an ECDT is not fatal. */
status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
goto error1;
}
/*
* Maybe EC region is required at bus_scan/acpi_get_devices. So it
* is necessary to enable it as early as possible.
*/
acpi_boot_ec_enable();
printk(KERN_INFO PREFIX "Interpreter enabled\n");
/* Initialize sleep structures */
acpi_sleep_init();
/*
* Get the system interrupt model and evaluate \_PIC.
*/
result = acpi_bus_init_irq();
if (result)
goto error1;
/*
* Register the for all standard device notifications.
*/
status =
acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
&acpi_bus_notify, NULL);
if (ACPI_FAILURE(status)) {
printk(KERN_ERR PREFIX
"Unable to register for device notifications\n");
goto error1;
}
/*
* Create the top ACPI proc directory
*/
acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
return 0;
/* Mimic structured exception handling */
error1:
acpi_terminate();
return -ENODEV;
}
struct kobject *acpi_kobj;
static int __init acpi_init(void)
{
int result = 0;
if (acpi_disabled) {
printk(KERN_INFO PREFIX "Interpreter disabled.\n");
return -ENODEV;
}
acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
if (!acpi_kobj) {
printk(KERN_WARNING "%s: kset create error\n", __func__);
acpi_kobj = NULL;
}
result = acpi_bus_init();
if (!result) {
pci_mmcfg_late_init();
if (!(pm_flags & PM_APM))
pm_flags |= PM_ACPI;
else {
printk(KERN_INFO PREFIX
"APM is already active, exiting\n");
disable_acpi();
result = -ENODEV;
}
} else
disable_acpi();
/*
* If the laptop falls into the DMI check table, the power state check
* will be disabled in the course of device power transistion.
*/
dmi_check_system(power_nocheck_dmi_table);
return result;
}
subsys_initcall(acpi_init);