xref: /openbmc/linux/drivers/acpi/acpica/evgpe.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /******************************************************************************
2  *
3  * Module Name: evgpe - General Purpose Event handling and dispatch
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2010, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acevents.h"
47 #include "acnamesp.h"
48 
49 #define _COMPONENT          ACPI_EVENTS
50 ACPI_MODULE_NAME("evgpe")
51 
52 /* Local prototypes */
53 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context);
54 
55 /*******************************************************************************
56  *
57  * FUNCTION:    acpi_ev_update_gpe_enable_mask
58  *
59  * PARAMETERS:  gpe_event_info          - GPE to update
60  *
61  * RETURN:      Status
62  *
63  * DESCRIPTION: Updates GPE register enable mask based upon whether there are
64  *              runtime references to this GPE
65  *
66  ******************************************************************************/
67 
68 acpi_status
69 acpi_ev_update_gpe_enable_mask(struct acpi_gpe_event_info *gpe_event_info)
70 {
71 	struct acpi_gpe_register_info *gpe_register_info;
72 	u32 register_bit;
73 
74 	ACPI_FUNCTION_TRACE(ev_update_gpe_enable_mask);
75 
76 	gpe_register_info = gpe_event_info->register_info;
77 	if (!gpe_register_info) {
78 		return_ACPI_STATUS(AE_NOT_EXIST);
79 	}
80 
81 	register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info,
82 						gpe_register_info);
83 
84 	/* Clear the run bit up front */
85 
86 	ACPI_CLEAR_BIT(gpe_register_info->enable_for_run, register_bit);
87 
88 	/* Set the mask bit only if there are references to this GPE */
89 
90 	if (gpe_event_info->runtime_count) {
91 		ACPI_SET_BIT(gpe_register_info->enable_for_run, (u8)register_bit);
92 	}
93 
94 	return_ACPI_STATUS(AE_OK);
95 }
96 
97 /*******************************************************************************
98  *
99  * FUNCTION:    acpi_ev_enable_gpe
100  *
101  * PARAMETERS:  gpe_event_info  - GPE to enable
102  *
103  * RETURN:      Status
104  *
105  * DESCRIPTION: Clear the given GPE from stale events and enable it.
106  *
107  ******************************************************************************/
108 acpi_status
109 acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
110 {
111 	acpi_status status;
112 
113 	ACPI_FUNCTION_TRACE(ev_enable_gpe);
114 
115 	/*
116 	 * We will only allow a GPE to be enabled if it has either an
117 	 * associated method (_Lxx/_Exx) or a handler. Otherwise, the
118 	 * GPE will be immediately disabled by acpi_ev_gpe_dispatch the
119 	 * first time it fires.
120 	 */
121 	if (!(gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK)) {
122 		return_ACPI_STATUS(AE_NO_HANDLER);
123 	}
124 
125 	/* Clear the GPE (of stale events) */
126 	status = acpi_hw_clear_gpe(gpe_event_info);
127 	if (ACPI_FAILURE(status)) {
128 		return_ACPI_STATUS(status);
129 	}
130 
131 	/* Enable the requested GPE */
132 	status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);
133 
134 	return_ACPI_STATUS(status);
135 }
136 
137 
138 /*******************************************************************************
139  *
140  * FUNCTION:    acpi_raw_enable_gpe
141  *
142  * PARAMETERS:  gpe_event_info  - GPE to enable
143  *
144  * RETURN:      Status
145  *
146  * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
147  *              hardware-enabled.
148  *
149  ******************************************************************************/
150 
151 acpi_status acpi_raw_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
152 {
153 	acpi_status status = AE_OK;
154 
155 	if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) {
156 		return_ACPI_STATUS(AE_LIMIT);
157 	}
158 
159 	gpe_event_info->runtime_count++;
160 	if (gpe_event_info->runtime_count == 1) {
161 		status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
162 		if (ACPI_SUCCESS(status)) {
163 			status = acpi_ev_enable_gpe(gpe_event_info);
164 		}
165 
166 		if (ACPI_FAILURE(status)) {
167 			gpe_event_info->runtime_count--;
168 		}
169 	}
170 
171 	return_ACPI_STATUS(status);
172 }
173 
174 /*******************************************************************************
175  *
176  * FUNCTION:    acpi_raw_disable_gpe
177  *
178  * PARAMETERS:  gpe_event_info  - GPE to disable
179  *
180  * RETURN:      Status
181  *
182  * DESCRIPTION: Remove a reference to a GPE. When the last reference is
183  *              removed, the GPE is hardware-disabled.
184  *
185  ******************************************************************************/
186 
187 acpi_status acpi_raw_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
188 {
189 	acpi_status status = AE_OK;
190 
191 	if (!gpe_event_info->runtime_count) {
192 		return_ACPI_STATUS(AE_LIMIT);
193 	}
194 
195 	gpe_event_info->runtime_count--;
196 	if (!gpe_event_info->runtime_count) {
197 		status = acpi_ev_update_gpe_enable_mask(gpe_event_info);
198 		if (ACPI_SUCCESS(status)) {
199 			status = acpi_hw_low_set_gpe(gpe_event_info,
200 						     ACPI_GPE_DISABLE);
201 		}
202 
203 		if (ACPI_FAILURE(status)) {
204 			gpe_event_info->runtime_count++;
205 		}
206 	}
207 
208 	return_ACPI_STATUS(status);
209 }
210 
211 /*******************************************************************************
212  *
213  * FUNCTION:    acpi_ev_low_get_gpe_info
214  *
215  * PARAMETERS:  gpe_number          - Raw GPE number
216  *              gpe_block           - A GPE info block
217  *
218  * RETURN:      A GPE event_info struct. NULL if not a valid GPE (The gpe_number
219  *              is not within the specified GPE block)
220  *
221  * DESCRIPTION: Returns the event_info struct associated with this GPE. This is
222  *              the low-level implementation of ev_get_gpe_event_info.
223  *
224  ******************************************************************************/
225 
226 struct acpi_gpe_event_info *acpi_ev_low_get_gpe_info(u32 gpe_number,
227 						     struct acpi_gpe_block_info
228 						     *gpe_block)
229 {
230 	u32 gpe_index;
231 
232 	/*
233 	 * Validate that the gpe_number is within the specified gpe_block.
234 	 * (Two steps)
235 	 */
236 	if (!gpe_block || (gpe_number < gpe_block->block_base_number)) {
237 		return (NULL);
238 	}
239 
240 	gpe_index = gpe_number - gpe_block->block_base_number;
241 	if (gpe_index >= gpe_block->gpe_count) {
242 		return (NULL);
243 	}
244 
245 	return (&gpe_block->event_info[gpe_index]);
246 }
247 
248 
249 /*******************************************************************************
250  *
251  * FUNCTION:    acpi_ev_get_gpe_event_info
252  *
253  * PARAMETERS:  gpe_device          - Device node. NULL for GPE0/GPE1
254  *              gpe_number          - Raw GPE number
255  *
256  * RETURN:      A GPE event_info struct. NULL if not a valid GPE
257  *
258  * DESCRIPTION: Returns the event_info struct associated with this GPE.
259  *              Validates the gpe_block and the gpe_number
260  *
261  *              Should be called only when the GPE lists are semaphore locked
262  *              and not subject to change.
263  *
264  ******************************************************************************/
265 
266 struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
267 						       u32 gpe_number)
268 {
269 	union acpi_operand_object *obj_desc;
270 	struct acpi_gpe_event_info *gpe_info;
271 	u32 i;
272 
273 	ACPI_FUNCTION_ENTRY();
274 
275 	/* A NULL gpe_device means use the FADT-defined GPE block(s) */
276 
277 	if (!gpe_device) {
278 
279 		/* Examine GPE Block 0 and 1 (These blocks are permanent) */
280 
281 		for (i = 0; i < ACPI_MAX_GPE_BLOCKS; i++) {
282 			gpe_info = acpi_ev_low_get_gpe_info(gpe_number,
283 							    acpi_gbl_gpe_fadt_blocks
284 							    [i]);
285 			if (gpe_info) {
286 				return (gpe_info);
287 			}
288 		}
289 
290 		/* The gpe_number was not in the range of either FADT GPE block */
291 
292 		return (NULL);
293 	}
294 
295 	/* A Non-NULL gpe_device means this is a GPE Block Device */
296 
297 	obj_desc = acpi_ns_get_attached_object((struct acpi_namespace_node *)
298 					       gpe_device);
299 	if (!obj_desc || !obj_desc->device.gpe_block) {
300 		return (NULL);
301 	}
302 
303 	return (acpi_ev_low_get_gpe_info
304 		(gpe_number, obj_desc->device.gpe_block));
305 }
306 
307 /*******************************************************************************
308  *
309  * FUNCTION:    acpi_ev_gpe_detect
310  *
311  * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
312  *                                    Can have multiple GPE blocks attached.
313  *
314  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
315  *
316  * DESCRIPTION: Detect if any GP events have occurred. This function is
317  *              executed at interrupt level.
318  *
319  ******************************************************************************/
320 
321 u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info * gpe_xrupt_list)
322 {
323 	acpi_status status;
324 	struct acpi_gpe_block_info *gpe_block;
325 	struct acpi_gpe_register_info *gpe_register_info;
326 	u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
327 	u8 enabled_status_byte;
328 	u32 status_reg;
329 	u32 enable_reg;
330 	acpi_cpu_flags flags;
331 	u32 i;
332 	u32 j;
333 
334 	ACPI_FUNCTION_NAME(ev_gpe_detect);
335 
336 	/* Check for the case where there are no GPEs */
337 
338 	if (!gpe_xrupt_list) {
339 		return (int_status);
340 	}
341 
342 	/*
343 	 * We need to obtain the GPE lock for both the data structs and registers
344 	 * Note: Not necessary to obtain the hardware lock, since the GPE
345 	 * registers are owned by the gpe_lock.
346 	 */
347 	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
348 
349 	/* Examine all GPE blocks attached to this interrupt level */
350 
351 	gpe_block = gpe_xrupt_list->gpe_block_list_head;
352 	while (gpe_block) {
353 		/*
354 		 * Read all of the 8-bit GPE status and enable registers in this GPE
355 		 * block, saving all of them. Find all currently active GP events.
356 		 */
357 		for (i = 0; i < gpe_block->register_count; i++) {
358 
359 			/* Get the next status/enable pair */
360 
361 			gpe_register_info = &gpe_block->register_info[i];
362 
363 			/* Read the Status Register */
364 
365 			status =
366 			    acpi_hw_read(&status_reg,
367 					 &gpe_register_info->status_address);
368 			if (ACPI_FAILURE(status)) {
369 				goto unlock_and_exit;
370 			}
371 
372 			/* Read the Enable Register */
373 
374 			status =
375 			    acpi_hw_read(&enable_reg,
376 					 &gpe_register_info->enable_address);
377 			if (ACPI_FAILURE(status)) {
378 				goto unlock_and_exit;
379 			}
380 
381 			ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
382 					  "Read GPE Register at GPE%X: Status=%02X, Enable=%02X\n",
383 					  gpe_register_info->base_gpe_number,
384 					  status_reg, enable_reg));
385 
386 			/* Check if there is anything active at all in this register */
387 
388 			enabled_status_byte = (u8) (status_reg & enable_reg);
389 			if (!enabled_status_byte) {
390 
391 				/* No active GPEs in this register, move on */
392 
393 				continue;
394 			}
395 
396 			/* Now look at the individual GPEs in this byte register */
397 
398 			for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {
399 
400 				/* Examine one GPE bit */
401 
402 				if (enabled_status_byte & (1 << j)) {
403 					/*
404 					 * Found an active GPE. Dispatch the event to a handler
405 					 * or method.
406 					 */
407 					int_status |=
408 					    acpi_ev_gpe_dispatch(&gpe_block->
409 						event_info[((acpi_size) i * ACPI_GPE_REGISTER_WIDTH) + j], j + gpe_register_info->base_gpe_number);
410 				}
411 			}
412 		}
413 
414 		gpe_block = gpe_block->next;
415 	}
416 
417       unlock_and_exit:
418 
419 	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
420 	return (int_status);
421 }
422 
423 /*******************************************************************************
424  *
425  * FUNCTION:    acpi_ev_asynch_execute_gpe_method
426  *
427  * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
428  *
429  * RETURN:      None
430  *
431  * DESCRIPTION: Perform the actual execution of a GPE control method. This
432  *              function is called from an invocation of acpi_os_execute and
433  *              therefore does NOT execute at interrupt level - so that
434  *              the control method itself is not executed in the context of
435  *              an interrupt handler.
436  *
437  ******************************************************************************/
438 static void acpi_ev_asynch_enable_gpe(void *context);
439 
440 static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
441 {
442 	struct acpi_gpe_event_info *gpe_event_info = (void *)context;
443 	acpi_status status;
444 	struct acpi_gpe_event_info local_gpe_event_info;
445 	struct acpi_evaluate_info *info;
446 
447 	ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);
448 
449 	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
450 	if (ACPI_FAILURE(status)) {
451 		return_VOID;
452 	}
453 
454 	/* Must revalidate the gpe_number/gpe_block */
455 
456 	if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
457 		status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
458 		return_VOID;
459 	}
460 
461 	/*
462 	 * Take a snapshot of the GPE info for this level - we copy the info to
463 	 * prevent a race condition with remove_handler/remove_block.
464 	 */
465 	ACPI_MEMCPY(&local_gpe_event_info, gpe_event_info,
466 		    sizeof(struct acpi_gpe_event_info));
467 
468 	status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
469 	if (ACPI_FAILURE(status)) {
470 		return_VOID;
471 	}
472 
473 	/*
474 	 * Must check for control method type dispatch one more time to avoid a
475 	 * race with ev_gpe_install_handler
476 	 */
477 	if ((local_gpe_event_info.flags & ACPI_GPE_DISPATCH_MASK) ==
478 	    ACPI_GPE_DISPATCH_METHOD) {
479 
480 		/* Allocate the evaluation information block */
481 
482 		info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
483 		if (!info) {
484 			status = AE_NO_MEMORY;
485 		} else {
486 			/*
487 			 * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the _Lxx/_Exx
488 			 * control method that corresponds to this GPE
489 			 */
490 			info->prefix_node =
491 			    local_gpe_event_info.dispatch.method_node;
492 			info->flags = ACPI_IGNORE_RETURN_VALUE;
493 
494 			status = acpi_ns_evaluate(info);
495 			ACPI_FREE(info);
496 		}
497 
498 		if (ACPI_FAILURE(status)) {
499 			ACPI_EXCEPTION((AE_INFO, status,
500 					"while evaluating GPE method [%4.4s]",
501 					acpi_ut_get_node_name
502 					(local_gpe_event_info.dispatch.
503 					 method_node)));
504 		}
505 	}
506 	/* Defer enabling of GPE until all notify handlers are done */
507 	acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_ev_asynch_enable_gpe,
508 				gpe_event_info);
509 	return_VOID;
510 }
511 
512 static void acpi_ev_asynch_enable_gpe(void *context)
513 {
514 	struct acpi_gpe_event_info *gpe_event_info = context;
515 	acpi_status status;
516 	if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
517 	    ACPI_GPE_LEVEL_TRIGGERED) {
518 		/*
519 		 * GPE is level-triggered, we clear the GPE status bit after handling
520 		 * the event.
521 		 */
522 		status = acpi_hw_clear_gpe(gpe_event_info);
523 		if (ACPI_FAILURE(status)) {
524 			return_VOID;
525 		}
526 	}
527 
528 	/*
529 	 * Enable this GPE, conditionally. This means that the GPE will only be
530 	 * physically enabled if the enable_for_run bit is set in the event_info
531 	 */
532 	(void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_COND_ENABLE);
533 
534 	return_VOID;
535 }
536 
537 /*******************************************************************************
538  *
539  * FUNCTION:    acpi_ev_gpe_dispatch
540  *
541  * PARAMETERS:  gpe_event_info  - Info for this GPE
542  *              gpe_number      - Number relative to the parent GPE block
543  *
544  * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
545  *
546  * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
547  *              or method (e.g. _Lxx/_Exx) handler.
548  *
549  *              This function executes at interrupt level.
550  *
551  ******************************************************************************/
552 
553 u32
554 acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
555 {
556 	acpi_status status;
557 
558 	ACPI_FUNCTION_TRACE(ev_gpe_dispatch);
559 
560 	acpi_os_gpe_count(gpe_number);
561 
562 	/*
563 	 * If edge-triggered, clear the GPE status bit now. Note that
564 	 * level-triggered events are cleared after the GPE is serviced.
565 	 */
566 	if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
567 	    ACPI_GPE_EDGE_TRIGGERED) {
568 		status = acpi_hw_clear_gpe(gpe_event_info);
569 		if (ACPI_FAILURE(status)) {
570 			ACPI_EXCEPTION((AE_INFO, status,
571 					"Unable to clear GPE[0x%2X]",
572 					gpe_number));
573 			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
574 		}
575 	}
576 
577 	/*
578 	 * Dispatch the GPE to either an installed handler, or the control method
579 	 * associated with this GPE (_Lxx or _Exx). If a handler exists, we invoke
580 	 * it and do not attempt to run the method. If there is neither a handler
581 	 * nor a method, we disable this GPE to prevent further such pointless
582 	 * events from firing.
583 	 */
584 	switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
585 	case ACPI_GPE_DISPATCH_HANDLER:
586 
587 		/*
588 		 * Invoke the installed handler (at interrupt level)
589 		 * Ignore return status for now.
590 		 * TBD: leave GPE disabled on error?
591 		 */
592 		(void)gpe_event_info->dispatch.handler->address(gpe_event_info->
593 								dispatch.
594 								handler->
595 								context);
596 
597 		/* It is now safe to clear level-triggered events. */
598 
599 		if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
600 		    ACPI_GPE_LEVEL_TRIGGERED) {
601 			status = acpi_hw_clear_gpe(gpe_event_info);
602 			if (ACPI_FAILURE(status)) {
603 				ACPI_EXCEPTION((AE_INFO, status,
604 					"Unable to clear GPE[0x%2X]",
605 						gpe_number));
606 				return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
607 			}
608 		}
609 		break;
610 
611 	case ACPI_GPE_DISPATCH_METHOD:
612 
613 		/*
614 		 * Disable the GPE, so it doesn't keep firing before the method has a
615 		 * chance to run (it runs asynchronously with interrupts enabled).
616 		 */
617 		status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
618 		if (ACPI_FAILURE(status)) {
619 			ACPI_EXCEPTION((AE_INFO, status,
620 					"Unable to disable GPE[0x%2X]",
621 					gpe_number));
622 			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
623 		}
624 
625 		/*
626 		 * Execute the method associated with the GPE
627 		 * NOTE: Level-triggered GPEs are cleared after the method completes.
628 		 */
629 		status = acpi_os_execute(OSL_GPE_HANDLER,
630 					 acpi_ev_asynch_execute_gpe_method,
631 					 gpe_event_info);
632 		if (ACPI_FAILURE(status)) {
633 			ACPI_EXCEPTION((AE_INFO, status,
634 					"Unable to queue handler for GPE[0x%2X] - event disabled",
635 					gpe_number));
636 		}
637 		break;
638 
639 	default:
640 
641 		/*
642 		 * No handler or method to run!
643 		 * 03/2010: This case should no longer be possible. We will not allow
644 		 * a GPE to be enabled if it has no handler or method.
645 		 */
646 		ACPI_ERROR((AE_INFO,
647 			    "No handler or method for GPE[0x%2X], disabling event",
648 			    gpe_number));
649 
650 		/*
651 		 * Disable the GPE. The GPE will remain disabled a handler
652 		 * is installed or ACPICA is restarted.
653 		 */
654 		status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
655 		if (ACPI_FAILURE(status)) {
656 			ACPI_EXCEPTION((AE_INFO, status,
657 					"Unable to disable GPE[0x%2X]",
658 					gpe_number));
659 			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
660 		}
661 		break;
662 	}
663 
664 	return_UINT32(ACPI_INTERRUPT_HANDLED);
665 }
666