Pull trivial into test branch
[linux-2.6] / drivers / acpi / bus.c
1 /*
2  *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
3  *
4  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
5  *
6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or (at
11  *  your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful, but
14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  *  General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License along
19  *  with this program; if not, write to the Free Software Foundation, Inc.,
20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21  *
22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23  */
24
25 #include <linux/module.h>
26 #include <linux/init.h>
27 #include <linux/ioport.h>
28 #include <linux/list.h>
29 #include <linux/sched.h>
30 #include <linux/pm.h>
31 #include <linux/pm_legacy.h>
32 #include <linux/device.h>
33 #include <linux/proc_fs.h>
34 #ifdef CONFIG_X86
35 #include <asm/mpspec.h>
36 #endif
37 #include <acpi/acpi_bus.h>
38 #include <acpi/acpi_drivers.h>
39
40 #define _COMPONENT              ACPI_BUS_COMPONENT
41 ACPI_MODULE_NAME("acpi_bus")
42 #ifdef  CONFIG_X86
43 extern void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger);
44 #endif
45
46 struct fadt_descriptor acpi_fadt;
47 EXPORT_SYMBOL(acpi_fadt);
48
49 struct acpi_device *acpi_root;
50 struct proc_dir_entry *acpi_root_dir;
51 EXPORT_SYMBOL(acpi_root_dir);
52
53 #define STRUCT_TO_INT(s)        (*((int*)&s))
54
55 /* --------------------------------------------------------------------------
56                                 Device Management
57    -------------------------------------------------------------------------- */
58
59 int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
60 {
61         acpi_status status = AE_OK;
62
63
64         if (!device)
65                 return -EINVAL;
66
67         /* TBD: Support fixed-feature devices */
68
69         status = acpi_get_data(handle, acpi_bus_data_handler, (void **)device);
70         if (ACPI_FAILURE(status) || !*device) {
71                 ACPI_EXCEPTION((AE_INFO, status, "No context for object [%p]", handle));
72                 return -ENODEV;
73         }
74
75         return 0;
76 }
77
78 EXPORT_SYMBOL(acpi_bus_get_device);
79
80 int acpi_bus_get_status(struct acpi_device *device)
81 {
82         acpi_status status = AE_OK;
83         unsigned long sta = 0;
84
85
86         if (!device)
87                 return -EINVAL;
88
89         /*
90          * Evaluate _STA if present.
91          */
92         if (device->flags.dynamic_status) {
93                 status =
94                     acpi_evaluate_integer(device->handle, "_STA", NULL, &sta);
95                 if (ACPI_FAILURE(status))
96                         return -ENODEV;
97                 STRUCT_TO_INT(device->status) = (int)sta;
98         }
99
100         /*
101          * Otherwise we assume the status of our parent (unless we don't
102          * have one, in which case status is implied).
103          */
104         else if (device->parent)
105                 device->status = device->parent->status;
106         else
107                 STRUCT_TO_INT(device->status) = 0x0F;
108
109         if (device->status.functional && !device->status.present) {
110                 printk(KERN_WARNING PREFIX "Device [%s] status [%08x]: "
111                        "functional but not present; setting present\n",
112                        device->pnp.bus_id, (u32) STRUCT_TO_INT(device->status));
113                 device->status.present = 1;
114         }
115
116         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
117                           device->pnp.bus_id,
118                           (u32) STRUCT_TO_INT(device->status)));
119
120         return 0;
121 }
122
123 EXPORT_SYMBOL(acpi_bus_get_status);
124
125 /* --------------------------------------------------------------------------
126                                  Power Management
127    -------------------------------------------------------------------------- */
128
129 int acpi_bus_get_power(acpi_handle handle, int *state)
130 {
131         int result = 0;
132         acpi_status status = 0;
133         struct acpi_device *device = NULL;
134         unsigned long psc = 0;
135
136
137         result = acpi_bus_get_device(handle, &device);
138         if (result)
139                 return result;
140
141         *state = ACPI_STATE_UNKNOWN;
142
143         if (!device->flags.power_manageable) {
144                 /* TBD: Non-recursive algorithm for walking up hierarchy */
145                 if (device->parent)
146                         *state = device->parent->power.state;
147                 else
148                         *state = ACPI_STATE_D0;
149         } else {
150                 /*
151                  * Get the device's power state either directly (via _PSC) or 
152                  * indirectly (via power resources).
153                  */
154                 if (device->power.flags.explicit_get) {
155                         status = acpi_evaluate_integer(device->handle, "_PSC",
156                                                        NULL, &psc);
157                         if (ACPI_FAILURE(status))
158                                 return -ENODEV;
159                         device->power.state = (int)psc;
160                 } else if (device->power.flags.power_resources) {
161                         result = acpi_power_get_inferred_state(device);
162                         if (result)
163                                 return result;
164                 }
165
166                 *state = device->power.state;
167         }
168
169         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
170                           device->pnp.bus_id, device->power.state));
171
172         return 0;
173 }
174
175 EXPORT_SYMBOL(acpi_bus_get_power);
176
177 int acpi_bus_set_power(acpi_handle handle, int state)
178 {
179         int result = 0;
180         acpi_status status = AE_OK;
181         struct acpi_device *device = NULL;
182         char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
183
184
185         result = acpi_bus_get_device(handle, &device);
186         if (result)
187                 return result;
188
189         if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
190                 return -EINVAL;
191
192         /* Make sure this is a valid target state */
193
194         if (!device->flags.power_manageable) {
195                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable",
196                                 device->kobj.name));
197                 return -ENODEV;
198         }
199         /*
200          * Get device's current power state if it's unknown
201          * This means device power state isn't initialized or previous setting failed
202          */
203         if (!device->flags.force_power_state) {
204                 if (device->power.state == ACPI_STATE_UNKNOWN)
205                         acpi_bus_get_power(device->handle, &device->power.state);
206                 if (state == device->power.state) {
207                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
208                                           state));
209                         return 0;
210                 }
211         }
212         if (!device->power.states[state].flags.valid) {
213                 printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
214                 return -ENODEV;
215         }
216         if (device->parent && (state < device->parent->power.state)) {
217                 printk(KERN_WARNING PREFIX
218                               "Cannot set device to a higher-powered"
219                               " state than parent\n");
220                 return -ENODEV;
221         }
222
223         /*
224          * Transition Power
225          * ----------------
226          * On transitions to a high-powered state we first apply power (via
227          * power resources) then evalute _PSx.  Conversly for transitions to
228          * a lower-powered state.
229          */
230         if (state < device->power.state) {
231                 if (device->power.flags.power_resources) {
232                         result = acpi_power_transition(device, state);
233                         if (result)
234                                 goto end;
235                 }
236                 if (device->power.states[state].flags.explicit_set) {
237                         status = acpi_evaluate_object(device->handle,
238                                                       object_name, NULL, NULL);
239                         if (ACPI_FAILURE(status)) {
240                                 result = -ENODEV;
241                                 goto end;
242                         }
243                 }
244         } else {
245                 if (device->power.states[state].flags.explicit_set) {
246                         status = acpi_evaluate_object(device->handle,
247                                                       object_name, NULL, NULL);
248                         if (ACPI_FAILURE(status)) {
249                                 result = -ENODEV;
250                                 goto end;
251                         }
252                 }
253                 if (device->power.flags.power_resources) {
254                         result = acpi_power_transition(device, state);
255                         if (result)
256                                 goto end;
257                 }
258         }
259
260       end:
261         if (result)
262                 printk(KERN_WARNING PREFIX
263                               "Transitioning device [%s] to D%d\n",
264                               device->pnp.bus_id, state);
265         else
266                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
267                                   "Device [%s] transitioned to D%d\n",
268                                   device->pnp.bus_id, state));
269
270         return result;
271 }
272
273 EXPORT_SYMBOL(acpi_bus_set_power);
274
275 /* --------------------------------------------------------------------------
276                                 Event Management
277    -------------------------------------------------------------------------- */
278
279 static DEFINE_SPINLOCK(acpi_bus_event_lock);
280
281 LIST_HEAD(acpi_bus_event_list);
282 DECLARE_WAIT_QUEUE_HEAD(acpi_bus_event_queue);
283
284 extern int event_is_open;
285
286 int acpi_bus_generate_event(struct acpi_device *device, u8 type, int data)
287 {
288         struct acpi_bus_event *event = NULL;
289         unsigned long flags = 0;
290
291
292         if (!device)
293                 return -EINVAL;
294
295         /* drop event on the floor if no one's listening */
296         if (!event_is_open)
297                 return 0;
298
299         event = kmalloc(sizeof(struct acpi_bus_event), GFP_ATOMIC);
300         if (!event)
301                 return -ENOMEM;
302
303         strcpy(event->device_class, device->pnp.device_class);
304         strcpy(event->bus_id, device->pnp.bus_id);
305         event->type = type;
306         event->data = data;
307
308         spin_lock_irqsave(&acpi_bus_event_lock, flags);
309         list_add_tail(&event->node, &acpi_bus_event_list);
310         spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
311
312         wake_up_interruptible(&acpi_bus_event_queue);
313
314         return 0;
315 }
316
317 EXPORT_SYMBOL(acpi_bus_generate_event);
318
319 int acpi_bus_receive_event(struct acpi_bus_event *event)
320 {
321         unsigned long flags = 0;
322         struct acpi_bus_event *entry = NULL;
323
324         DECLARE_WAITQUEUE(wait, current);
325
326
327         if (!event)
328                 return -EINVAL;
329
330         if (list_empty(&acpi_bus_event_list)) {
331
332                 set_current_state(TASK_INTERRUPTIBLE);
333                 add_wait_queue(&acpi_bus_event_queue, &wait);
334
335                 if (list_empty(&acpi_bus_event_list))
336                         schedule();
337
338                 remove_wait_queue(&acpi_bus_event_queue, &wait);
339                 set_current_state(TASK_RUNNING);
340
341                 if (signal_pending(current))
342                         return -ERESTARTSYS;
343         }
344
345         spin_lock_irqsave(&acpi_bus_event_lock, flags);
346         entry =
347             list_entry(acpi_bus_event_list.next, struct acpi_bus_event, node);
348         if (entry)
349                 list_del(&entry->node);
350         spin_unlock_irqrestore(&acpi_bus_event_lock, flags);
351
352         if (!entry)
353                 return -ENODEV;
354
355         memcpy(event, entry, sizeof(struct acpi_bus_event));
356
357         kfree(entry);
358
359         return 0;
360 }
361
362 EXPORT_SYMBOL(acpi_bus_receive_event);
363
364 /* --------------------------------------------------------------------------
365                              Notification Handling
366    -------------------------------------------------------------------------- */
367
368 static int
369 acpi_bus_check_device(struct acpi_device *device, int *status_changed)
370 {
371         acpi_status status = 0;
372         struct acpi_device_status old_status;
373
374
375         if (!device)
376                 return -EINVAL;
377
378         if (status_changed)
379                 *status_changed = 0;
380
381         old_status = device->status;
382
383         /*
384          * Make sure this device's parent is present before we go about
385          * messing with the device.
386          */
387         if (device->parent && !device->parent->status.present) {
388                 device->status = device->parent->status;
389                 if (STRUCT_TO_INT(old_status) != STRUCT_TO_INT(device->status)) {
390                         if (status_changed)
391                                 *status_changed = 1;
392                 }
393                 return 0;
394         }
395
396         status = acpi_bus_get_status(device);
397         if (ACPI_FAILURE(status))
398                 return -ENODEV;
399
400         if (STRUCT_TO_INT(old_status) == STRUCT_TO_INT(device->status))
401                 return 0;
402
403         if (status_changed)
404                 *status_changed = 1;
405
406         /*
407          * Device Insertion/Removal
408          */
409         if ((device->status.present) && !(old_status.present)) {
410                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
411                 /* TBD: Handle device insertion */
412         } else if (!(device->status.present) && (old_status.present)) {
413                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device removal detected\n"));
414                 /* TBD: Handle device removal */
415         }
416
417         return 0;
418 }
419
420 static int acpi_bus_check_scope(struct acpi_device *device)
421 {
422         int result = 0;
423         int status_changed = 0;
424
425
426         if (!device)
427                 return -EINVAL;
428
429         /* Status Change? */
430         result = acpi_bus_check_device(device, &status_changed);
431         if (result)
432                 return result;
433
434         if (!status_changed)
435                 return 0;
436
437         /*
438          * TBD: Enumerate child devices within this device's scope and
439          *       run acpi_bus_check_device()'s on them.
440          */
441
442         return 0;
443 }
444
445 /**
446  * acpi_bus_notify
447  * ---------------
448  * Callback for all 'system-level' device notifications (values 0x00-0x7F).
449  */
450 static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
451 {
452         int result = 0;
453         struct acpi_device *device = NULL;
454
455
456         if (acpi_bus_get_device(handle, &device))
457                 return;
458
459         switch (type) {
460
461         case ACPI_NOTIFY_BUS_CHECK:
462                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
463                                   "Received BUS CHECK notification for device [%s]\n",
464                                   device->pnp.bus_id));
465                 result = acpi_bus_check_scope(device);
466                 /* 
467                  * TBD: We'll need to outsource certain events to non-ACPI
468                  *      drivers via the device manager (device.c).
469                  */
470                 break;
471
472         case ACPI_NOTIFY_DEVICE_CHECK:
473                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
474                                   "Received DEVICE CHECK notification for device [%s]\n",
475                                   device->pnp.bus_id));
476                 result = acpi_bus_check_device(device, NULL);
477                 /* 
478                  * TBD: We'll need to outsource certain events to non-ACPI
479                  *      drivers via the device manager (device.c).
480                  */
481                 break;
482
483         case ACPI_NOTIFY_DEVICE_WAKE:
484                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
485                                   "Received DEVICE WAKE notification for device [%s]\n",
486                                   device->pnp.bus_id));
487                 /* TBD */
488                 break;
489
490         case ACPI_NOTIFY_EJECT_REQUEST:
491                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
492                                   "Received EJECT REQUEST notification for device [%s]\n",
493                                   device->pnp.bus_id));
494                 /* TBD */
495                 break;
496
497         case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
498                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
499                                   "Received DEVICE CHECK LIGHT notification for device [%s]\n",
500                                   device->pnp.bus_id));
501                 /* TBD: Exactly what does 'light' mean? */
502                 break;
503
504         case ACPI_NOTIFY_FREQUENCY_MISMATCH:
505                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
506                                   "Received FREQUENCY MISMATCH notification for device [%s]\n",
507                                   device->pnp.bus_id));
508                 /* TBD */
509                 break;
510
511         case ACPI_NOTIFY_BUS_MODE_MISMATCH:
512                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
513                                   "Received BUS MODE MISMATCH notification for device [%s]\n",
514                                   device->pnp.bus_id));
515                 /* TBD */
516                 break;
517
518         case ACPI_NOTIFY_POWER_FAULT:
519                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
520                                   "Received POWER FAULT notification for device [%s]\n",
521                                   device->pnp.bus_id));
522                 /* TBD */
523                 break;
524
525         default:
526                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
527                                   "Received unknown/unsupported notification [%08x]\n",
528                                   type));
529                 break;
530         }
531
532         return;
533 }
534
535 /* --------------------------------------------------------------------------
536                              Initialization/Cleanup
537    -------------------------------------------------------------------------- */
538
539 static int __init acpi_bus_init_irq(void)
540 {
541         acpi_status status = AE_OK;
542         union acpi_object arg = { ACPI_TYPE_INTEGER };
543         struct acpi_object_list arg_list = { 1, &arg };
544         char *message = NULL;
545
546
547         /* 
548          * Let the system know what interrupt model we are using by
549          * evaluating the \_PIC object, if exists.
550          */
551
552         switch (acpi_irq_model) {
553         case ACPI_IRQ_MODEL_PIC:
554                 message = "PIC";
555                 break;
556         case ACPI_IRQ_MODEL_IOAPIC:
557                 message = "IOAPIC";
558                 break;
559         case ACPI_IRQ_MODEL_IOSAPIC:
560                 message = "IOSAPIC";
561                 break;
562         default:
563                 printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
564                 return -ENODEV;
565         }
566
567         printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);
568
569         arg.integer.value = acpi_irq_model;
570
571         status = acpi_evaluate_object(NULL, "\\_PIC", &arg_list, NULL);
572         if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
573                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
574                 return -ENODEV;
575         }
576
577         return 0;
578 }
579
580 void __init acpi_early_init(void)
581 {
582         acpi_status status = AE_OK;
583         struct acpi_buffer buffer = { sizeof(acpi_fadt), &acpi_fadt };
584
585
586         if (acpi_disabled)
587                 return;
588
589         printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
590
591         /* enable workarounds, unless strict ACPI spec. compliance */
592         if (!acpi_strict)
593                 acpi_gbl_enable_interpreter_slack = TRUE;
594
595         status = acpi_initialize_subsystem();
596         if (ACPI_FAILURE(status)) {
597                 printk(KERN_ERR PREFIX
598                        "Unable to initialize the ACPI Interpreter\n");
599                 goto error0;
600         }
601
602         status = acpi_load_tables();
603         if (ACPI_FAILURE(status)) {
604                 printk(KERN_ERR PREFIX
605                        "Unable to load the System Description Tables\n");
606                 goto error0;
607         }
608
609         /*
610          * Get a separate copy of the FADT for use by other drivers.
611          */
612         status = acpi_get_table(ACPI_TABLE_ID_FADT, 1, &buffer);
613         if (ACPI_FAILURE(status)) {
614                 printk(KERN_ERR PREFIX "Unable to get the FADT\n");
615                 goto error0;
616         }
617 #ifdef CONFIG_X86
618         if (!acpi_ioapic) {
619                 extern acpi_interrupt_flags acpi_sci_flags;
620
621                 /* compatible (0) means level (3) */
622                 if (acpi_sci_flags.trigger == 0)
623                         acpi_sci_flags.trigger = 3;
624
625                 /* Set PIC-mode SCI trigger type */
626                 acpi_pic_sci_set_trigger(acpi_fadt.sci_int,
627                                          acpi_sci_flags.trigger);
628         } else {
629                 extern int acpi_sci_override_gsi;
630                 /*
631                  * now that acpi_fadt is initialized,
632                  * update it with result from INT_SRC_OVR parsing
633                  */
634                 acpi_fadt.sci_int = acpi_sci_override_gsi;
635         }
636 #endif
637
638         status =
639             acpi_enable_subsystem(~
640                                   (ACPI_NO_HARDWARE_INIT |
641                                    ACPI_NO_ACPI_ENABLE));
642         if (ACPI_FAILURE(status)) {
643                 printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
644                 goto error0;
645         }
646
647         return;
648
649       error0:
650         disable_acpi();
651         return;
652 }
653
654 static int __init acpi_bus_init(void)
655 {
656         int result = 0;
657         acpi_status status = AE_OK;
658         extern acpi_status acpi_os_initialize1(void);
659
660
661         status = acpi_os_initialize1();
662
663         status =
664             acpi_enable_subsystem(ACPI_NO_HARDWARE_INIT | ACPI_NO_ACPI_ENABLE);
665         if (ACPI_FAILURE(status)) {
666                 printk(KERN_ERR PREFIX
667                        "Unable to start the ACPI Interpreter\n");
668                 goto error1;
669         }
670
671         if (ACPI_FAILURE(status)) {
672                 printk(KERN_ERR PREFIX
673                        "Unable to initialize ACPI OS objects\n");
674                 goto error1;
675         }
676 #ifdef CONFIG_ACPI_EC
677         /*
678          * ACPI 2.0 requires the EC driver to be loaded and work before
679          * the EC device is found in the namespace (i.e. before acpi_initialize_objects()
680          * is called).
681          *
682          * This is accomplished by looking for the ECDT table, and getting 
683          * the EC parameters out of that.
684          */
685         status = acpi_ec_ecdt_probe();
686         /* Ignore result. Not having an ECDT is not fatal. */
687 #endif
688
689         status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
690         if (ACPI_FAILURE(status)) {
691                 printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
692                 goto error1;
693         }
694
695         printk(KERN_INFO PREFIX "Interpreter enabled\n");
696
697         /*
698          * Get the system interrupt model and evaluate \_PIC.
699          */
700         result = acpi_bus_init_irq();
701         if (result)
702                 goto error1;
703
704         /*
705          * Register the for all standard device notifications.
706          */
707         status =
708             acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
709                                         &acpi_bus_notify, NULL);
710         if (ACPI_FAILURE(status)) {
711                 printk(KERN_ERR PREFIX
712                        "Unable to register for device notifications\n");
713                 goto error1;
714         }
715
716         /*
717          * Create the top ACPI proc directory
718          */
719         acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);
720
721         return 0;
722
723         /* Mimic structured exception handling */
724       error1:
725         acpi_terminate();
726         return -ENODEV;
727 }
728
729 decl_subsys(acpi, NULL, NULL);
730
731 static int __init acpi_init(void)
732 {
733         int result = 0;
734
735
736         if (acpi_disabled) {
737                 printk(KERN_INFO PREFIX "Interpreter disabled.\n");
738                 return -ENODEV;
739         }
740
741         firmware_register(&acpi_subsys);
742
743         result = acpi_bus_init();
744
745         if (!result) {
746 #ifdef CONFIG_PM_LEGACY
747                 if (!PM_IS_ACTIVE())
748                         pm_active = 1;
749                 else {
750                         printk(KERN_INFO PREFIX
751                                "APM is already active, exiting\n");
752                         disable_acpi();
753                         result = -ENODEV;
754                 }
755 #endif
756         } else
757                 disable_acpi();
758
759         return result;
760 }
761
762 subsys_initcall(acpi_init);