Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/irq/manage.c | |
3 | * | |
a34db9b2 IM |
4 | * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar |
5 | * Copyright (C) 2005-2006 Thomas Gleixner | |
1da177e4 LT |
6 | * |
7 | * This file contains driver APIs to the irq subsystem. | |
8 | */ | |
9 | ||
10 | #include <linux/irq.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/random.h> | |
13 | #include <linux/interrupt.h> | |
14 | ||
15 | #include "internals.h" | |
16 | ||
17 | #ifdef CONFIG_SMP | |
18 | ||
1da177e4 LT |
19 | /** |
20 | * synchronize_irq - wait for pending IRQ handlers (on other CPUs) | |
1e5d5331 | 21 | * @irq: interrupt number to wait for |
1da177e4 LT |
22 | * |
23 | * This function waits for any pending IRQ handlers for this interrupt | |
24 | * to complete before returning. If you use this function while | |
25 | * holding a resource the IRQ handler may need you will deadlock. | |
26 | * | |
27 | * This function may be called - with care - from IRQ context. | |
28 | */ | |
29 | void synchronize_irq(unsigned int irq) | |
30 | { | |
31 | struct irq_desc *desc = irq_desc + irq; | |
32 | ||
c2b5a251 MW |
33 | if (irq >= NR_IRQS) |
34 | return; | |
35 | ||
1da177e4 LT |
36 | while (desc->status & IRQ_INPROGRESS) |
37 | cpu_relax(); | |
38 | } | |
1da177e4 LT |
39 | EXPORT_SYMBOL(synchronize_irq); |
40 | ||
771ee3b0 TG |
41 | /** |
42 | * irq_can_set_affinity - Check if the affinity of a given irq can be set | |
43 | * @irq: Interrupt to check | |
44 | * | |
45 | */ | |
46 | int irq_can_set_affinity(unsigned int irq) | |
47 | { | |
48 | struct irq_desc *desc = irq_desc + irq; | |
49 | ||
50 | if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip || | |
51 | !desc->chip->set_affinity) | |
52 | return 0; | |
53 | ||
54 | return 1; | |
55 | } | |
56 | ||
57 | /** | |
58 | * irq_set_affinity - Set the irq affinity of a given irq | |
59 | * @irq: Interrupt to set affinity | |
60 | * @cpumask: cpumask | |
61 | * | |
62 | */ | |
63 | int irq_set_affinity(unsigned int irq, cpumask_t cpumask) | |
64 | { | |
65 | struct irq_desc *desc = irq_desc + irq; | |
66 | ||
67 | if (!desc->chip->set_affinity) | |
68 | return -EINVAL; | |
69 | ||
70 | set_balance_irq_affinity(irq, cpumask); | |
71 | ||
72 | #ifdef CONFIG_GENERIC_PENDING_IRQ | |
73 | set_pending_irq(irq, cpumask); | |
74 | #else | |
75 | desc->affinity = cpumask; | |
76 | desc->chip->set_affinity(irq, cpumask); | |
77 | #endif | |
78 | return 0; | |
79 | } | |
80 | ||
1da177e4 LT |
81 | #endif |
82 | ||
83 | /** | |
84 | * disable_irq_nosync - disable an irq without waiting | |
85 | * @irq: Interrupt to disable | |
86 | * | |
87 | * Disable the selected interrupt line. Disables and Enables are | |
88 | * nested. | |
89 | * Unlike disable_irq(), this function does not ensure existing | |
90 | * instances of the IRQ handler have completed before returning. | |
91 | * | |
92 | * This function may be called from IRQ context. | |
93 | */ | |
94 | void disable_irq_nosync(unsigned int irq) | |
95 | { | |
34ffdb72 | 96 | struct irq_desc *desc = irq_desc + irq; |
1da177e4 LT |
97 | unsigned long flags; |
98 | ||
c2b5a251 MW |
99 | if (irq >= NR_IRQS) |
100 | return; | |
101 | ||
1da177e4 LT |
102 | spin_lock_irqsave(&desc->lock, flags); |
103 | if (!desc->depth++) { | |
104 | desc->status |= IRQ_DISABLED; | |
d1bef4ed | 105 | desc->chip->disable(irq); |
1da177e4 LT |
106 | } |
107 | spin_unlock_irqrestore(&desc->lock, flags); | |
108 | } | |
1da177e4 LT |
109 | EXPORT_SYMBOL(disable_irq_nosync); |
110 | ||
111 | /** | |
112 | * disable_irq - disable an irq and wait for completion | |
113 | * @irq: Interrupt to disable | |
114 | * | |
115 | * Disable the selected interrupt line. Enables and Disables are | |
116 | * nested. | |
117 | * This function waits for any pending IRQ handlers for this interrupt | |
118 | * to complete before returning. If you use this function while | |
119 | * holding a resource the IRQ handler may need you will deadlock. | |
120 | * | |
121 | * This function may be called - with care - from IRQ context. | |
122 | */ | |
123 | void disable_irq(unsigned int irq) | |
124 | { | |
34ffdb72 | 125 | struct irq_desc *desc = irq_desc + irq; |
1da177e4 | 126 | |
c2b5a251 MW |
127 | if (irq >= NR_IRQS) |
128 | return; | |
129 | ||
1da177e4 LT |
130 | disable_irq_nosync(irq); |
131 | if (desc->action) | |
132 | synchronize_irq(irq); | |
133 | } | |
1da177e4 LT |
134 | EXPORT_SYMBOL(disable_irq); |
135 | ||
136 | /** | |
137 | * enable_irq - enable handling of an irq | |
138 | * @irq: Interrupt to enable | |
139 | * | |
140 | * Undoes the effect of one call to disable_irq(). If this | |
141 | * matches the last disable, processing of interrupts on this | |
142 | * IRQ line is re-enabled. | |
143 | * | |
144 | * This function may be called from IRQ context. | |
145 | */ | |
146 | void enable_irq(unsigned int irq) | |
147 | { | |
34ffdb72 | 148 | struct irq_desc *desc = irq_desc + irq; |
1da177e4 LT |
149 | unsigned long flags; |
150 | ||
c2b5a251 MW |
151 | if (irq >= NR_IRQS) |
152 | return; | |
153 | ||
1da177e4 LT |
154 | spin_lock_irqsave(&desc->lock, flags); |
155 | switch (desc->depth) { | |
156 | case 0: | |
e8c4b9d0 | 157 | printk(KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); |
1da177e4 LT |
158 | WARN_ON(1); |
159 | break; | |
160 | case 1: { | |
3418d724 TG |
161 | unsigned int status = desc->status & ~IRQ_DISABLED; |
162 | ||
163 | /* Prevent probing on this irq: */ | |
164 | desc->status = status | IRQ_NOPROBE; | |
a4633adc | 165 | check_irq_resend(desc, irq); |
1da177e4 LT |
166 | /* fall-through */ |
167 | } | |
168 | default: | |
169 | desc->depth--; | |
170 | } | |
171 | spin_unlock_irqrestore(&desc->lock, flags); | |
172 | } | |
1da177e4 LT |
173 | EXPORT_SYMBOL(enable_irq); |
174 | ||
ba9a2331 TG |
175 | /** |
176 | * set_irq_wake - control irq power management wakeup | |
177 | * @irq: interrupt to control | |
178 | * @on: enable/disable power management wakeup | |
179 | * | |
15a647eb DB |
180 | * Enable/disable power management wakeup mode, which is |
181 | * disabled by default. Enables and disables must match, | |
182 | * just as they match for non-wakeup mode support. | |
183 | * | |
184 | * Wakeup mode lets this IRQ wake the system from sleep | |
185 | * states like "suspend to RAM". | |
ba9a2331 TG |
186 | */ |
187 | int set_irq_wake(unsigned int irq, unsigned int on) | |
188 | { | |
189 | struct irq_desc *desc = irq_desc + irq; | |
190 | unsigned long flags; | |
191 | int ret = -ENXIO; | |
15a647eb | 192 | int (*set_wake)(unsigned, unsigned) = desc->chip->set_wake; |
ba9a2331 | 193 | |
15a647eb DB |
194 | /* wakeup-capable irqs can be shared between drivers that |
195 | * don't need to have the same sleep mode behaviors. | |
196 | */ | |
ba9a2331 | 197 | spin_lock_irqsave(&desc->lock, flags); |
15a647eb DB |
198 | if (on) { |
199 | if (desc->wake_depth++ == 0) | |
200 | desc->status |= IRQ_WAKEUP; | |
201 | else | |
202 | set_wake = NULL; | |
203 | } else { | |
204 | if (desc->wake_depth == 0) { | |
205 | printk(KERN_WARNING "Unbalanced IRQ %d " | |
206 | "wake disable\n", irq); | |
207 | WARN_ON(1); | |
208 | } else if (--desc->wake_depth == 0) | |
209 | desc->status &= ~IRQ_WAKEUP; | |
210 | else | |
211 | set_wake = NULL; | |
212 | } | |
213 | if (set_wake) | |
ba9a2331 TG |
214 | ret = desc->chip->set_wake(irq, on); |
215 | spin_unlock_irqrestore(&desc->lock, flags); | |
216 | return ret; | |
217 | } | |
218 | EXPORT_SYMBOL(set_irq_wake); | |
219 | ||
1da177e4 LT |
220 | /* |
221 | * Internal function that tells the architecture code whether a | |
222 | * particular irq has been exclusively allocated or is available | |
223 | * for driver use. | |
224 | */ | |
225 | int can_request_irq(unsigned int irq, unsigned long irqflags) | |
226 | { | |
227 | struct irqaction *action; | |
228 | ||
6550c775 | 229 | if (irq >= NR_IRQS || irq_desc[irq].status & IRQ_NOREQUEST) |
1da177e4 LT |
230 | return 0; |
231 | ||
232 | action = irq_desc[irq].action; | |
233 | if (action) | |
3cca53b0 | 234 | if (irqflags & action->flags & IRQF_SHARED) |
1da177e4 LT |
235 | action = NULL; |
236 | ||
237 | return !action; | |
238 | } | |
239 | ||
6a6de9ef TG |
240 | void compat_irq_chip_set_default_handler(struct irq_desc *desc) |
241 | { | |
242 | /* | |
243 | * If the architecture still has not overriden | |
244 | * the flow handler then zap the default. This | |
245 | * should catch incorrect flow-type setting. | |
246 | */ | |
247 | if (desc->handle_irq == &handle_bad_irq) | |
248 | desc->handle_irq = NULL; | |
249 | } | |
250 | ||
1da177e4 LT |
251 | /* |
252 | * Internal function to register an irqaction - typically used to | |
253 | * allocate special interrupts that are part of the architecture. | |
254 | */ | |
06fcb0c6 | 255 | int setup_irq(unsigned int irq, struct irqaction *new) |
1da177e4 LT |
256 | { |
257 | struct irq_desc *desc = irq_desc + irq; | |
258 | struct irqaction *old, **p; | |
8b126b77 | 259 | const char *old_name = NULL; |
1da177e4 LT |
260 | unsigned long flags; |
261 | int shared = 0; | |
262 | ||
c2b5a251 MW |
263 | if (irq >= NR_IRQS) |
264 | return -EINVAL; | |
265 | ||
f1c2662c | 266 | if (desc->chip == &no_irq_chip) |
1da177e4 LT |
267 | return -ENOSYS; |
268 | /* | |
269 | * Some drivers like serial.c use request_irq() heavily, | |
270 | * so we have to be careful not to interfere with a | |
271 | * running system. | |
272 | */ | |
3cca53b0 | 273 | if (new->flags & IRQF_SAMPLE_RANDOM) { |
1da177e4 LT |
274 | /* |
275 | * This function might sleep, we want to call it first, | |
276 | * outside of the atomic block. | |
277 | * Yes, this might clear the entropy pool if the wrong | |
278 | * driver is attempted to be loaded, without actually | |
279 | * installing a new handler, but is this really a problem, | |
280 | * only the sysadmin is able to do this. | |
281 | */ | |
282 | rand_initialize_irq(irq); | |
283 | } | |
284 | ||
285 | /* | |
286 | * The following block of code has to be executed atomically | |
287 | */ | |
06fcb0c6 | 288 | spin_lock_irqsave(&desc->lock, flags); |
1da177e4 | 289 | p = &desc->action; |
06fcb0c6 IM |
290 | old = *p; |
291 | if (old) { | |
e76de9f8 TG |
292 | /* |
293 | * Can't share interrupts unless both agree to and are | |
294 | * the same type (level, edge, polarity). So both flag | |
3cca53b0 | 295 | * fields must have IRQF_SHARED set and the bits which |
e76de9f8 TG |
296 | * set the trigger type must match. |
297 | */ | |
3cca53b0 | 298 | if (!((old->flags & new->flags) & IRQF_SHARED) || |
8b126b77 AM |
299 | ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) { |
300 | old_name = old->name; | |
f5163427 | 301 | goto mismatch; |
8b126b77 | 302 | } |
f5163427 | 303 | |
284c6680 | 304 | #if defined(CONFIG_IRQ_PER_CPU) |
f5163427 | 305 | /* All handlers must agree on per-cpuness */ |
3cca53b0 TG |
306 | if ((old->flags & IRQF_PERCPU) != |
307 | (new->flags & IRQF_PERCPU)) | |
f5163427 DS |
308 | goto mismatch; |
309 | #endif | |
1da177e4 LT |
310 | |
311 | /* add new interrupt at end of irq queue */ | |
312 | do { | |
313 | p = &old->next; | |
314 | old = *p; | |
315 | } while (old); | |
316 | shared = 1; | |
317 | } | |
318 | ||
319 | *p = new; | |
f75d222b | 320 | |
950f4427 TG |
321 | /* Exclude IRQ from balancing */ |
322 | if (new->flags & IRQF_NOBALANCING) | |
323 | desc->status |= IRQ_NO_BALANCING; | |
324 | ||
1da177e4 | 325 | if (!shared) { |
6a6de9ef | 326 | irq_chip_set_defaults(desc->chip); |
e76de9f8 | 327 | |
f75d222b AD |
328 | #if defined(CONFIG_IRQ_PER_CPU) |
329 | if (new->flags & IRQF_PERCPU) | |
330 | desc->status |= IRQ_PER_CPU; | |
331 | #endif | |
332 | ||
e76de9f8 | 333 | /* Setup the type (level, edge polarity) if configured: */ |
3cca53b0 | 334 | if (new->flags & IRQF_TRIGGER_MASK) { |
e76de9f8 TG |
335 | if (desc->chip && desc->chip->set_type) |
336 | desc->chip->set_type(irq, | |
3cca53b0 | 337 | new->flags & IRQF_TRIGGER_MASK); |
e76de9f8 TG |
338 | else |
339 | /* | |
3cca53b0 | 340 | * IRQF_TRIGGER_* but the PIC does not support |
e76de9f8 TG |
341 | * multiple flow-types? |
342 | */ | |
3cca53b0 | 343 | printk(KERN_WARNING "No IRQF_TRIGGER set_type " |
e8c4b9d0 BH |
344 | "function for IRQ %d (%s)\n", irq, |
345 | desc->chip ? desc->chip->name : | |
346 | "unknown"); | |
e76de9f8 TG |
347 | } else |
348 | compat_irq_chip_set_default_handler(desc); | |
6a6de9ef | 349 | |
94d39e1f TG |
350 | desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | |
351 | IRQ_INPROGRESS); | |
352 | ||
353 | if (!(desc->status & IRQ_NOAUTOEN)) { | |
354 | desc->depth = 0; | |
355 | desc->status &= ~IRQ_DISABLED; | |
356 | if (desc->chip->startup) | |
357 | desc->chip->startup(irq); | |
358 | else | |
359 | desc->chip->enable(irq); | |
e76de9f8 TG |
360 | } else |
361 | /* Undo nested disables: */ | |
362 | desc->depth = 1; | |
1da177e4 | 363 | } |
8528b0f1 LT |
364 | /* Reset broken irq detection when installing new handler */ |
365 | desc->irq_count = 0; | |
366 | desc->irqs_unhandled = 0; | |
06fcb0c6 | 367 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
368 | |
369 | new->irq = irq; | |
370 | register_irq_proc(irq); | |
371 | new->dir = NULL; | |
372 | register_handler_proc(irq, new); | |
373 | ||
374 | return 0; | |
f5163427 DS |
375 | |
376 | mismatch: | |
3f050447 | 377 | #ifdef CONFIG_DEBUG_SHIRQ |
3cca53b0 | 378 | if (!(new->flags & IRQF_PROBE_SHARED)) { |
e8c4b9d0 | 379 | printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq); |
8b126b77 AM |
380 | if (old_name) |
381 | printk(KERN_ERR "current handler: %s\n", old_name); | |
13e87ec6 AM |
382 | dump_stack(); |
383 | } | |
3f050447 | 384 | #endif |
8b126b77 | 385 | spin_unlock_irqrestore(&desc->lock, flags); |
f5163427 | 386 | return -EBUSY; |
1da177e4 LT |
387 | } |
388 | ||
389 | /** | |
390 | * free_irq - free an interrupt | |
391 | * @irq: Interrupt line to free | |
392 | * @dev_id: Device identity to free | |
393 | * | |
394 | * Remove an interrupt handler. The handler is removed and if the | |
395 | * interrupt line is no longer in use by any driver it is disabled. | |
396 | * On a shared IRQ the caller must ensure the interrupt is disabled | |
397 | * on the card it drives before calling this function. The function | |
398 | * does not return until any executing interrupts for this IRQ | |
399 | * have completed. | |
400 | * | |
401 | * This function must not be called from interrupt context. | |
402 | */ | |
403 | void free_irq(unsigned int irq, void *dev_id) | |
404 | { | |
405 | struct irq_desc *desc; | |
406 | struct irqaction **p; | |
407 | unsigned long flags; | |
a304e1b8 | 408 | irqreturn_t (*handler)(int, void *) = NULL; |
1da177e4 | 409 | |
cd7b24bb | 410 | WARN_ON(in_interrupt()); |
1da177e4 LT |
411 | if (irq >= NR_IRQS) |
412 | return; | |
413 | ||
414 | desc = irq_desc + irq; | |
06fcb0c6 | 415 | spin_lock_irqsave(&desc->lock, flags); |
1da177e4 LT |
416 | p = &desc->action; |
417 | for (;;) { | |
06fcb0c6 | 418 | struct irqaction *action = *p; |
1da177e4 LT |
419 | |
420 | if (action) { | |
421 | struct irqaction **pp = p; | |
422 | ||
423 | p = &action->next; | |
424 | if (action->dev_id != dev_id) | |
425 | continue; | |
426 | ||
427 | /* Found it - now remove it from the list of entries */ | |
428 | *pp = action->next; | |
dbce706e | 429 | |
b77d6adc PBG |
430 | /* Currently used only by UML, might disappear one day.*/ |
431 | #ifdef CONFIG_IRQ_RELEASE_METHOD | |
d1bef4ed IM |
432 | if (desc->chip->release) |
433 | desc->chip->release(irq, dev_id); | |
b77d6adc | 434 | #endif |
dbce706e | 435 | |
1da177e4 LT |
436 | if (!desc->action) { |
437 | desc->status |= IRQ_DISABLED; | |
d1bef4ed IM |
438 | if (desc->chip->shutdown) |
439 | desc->chip->shutdown(irq); | |
1da177e4 | 440 | else |
d1bef4ed | 441 | desc->chip->disable(irq); |
1da177e4 | 442 | } |
06fcb0c6 | 443 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
444 | unregister_handler_proc(irq, action); |
445 | ||
446 | /* Make sure it's not being used on another CPU */ | |
447 | synchronize_irq(irq); | |
a304e1b8 DW |
448 | if (action->flags & IRQF_SHARED) |
449 | handler = action->handler; | |
1da177e4 LT |
450 | kfree(action); |
451 | return; | |
452 | } | |
e8c4b9d0 | 453 | printk(KERN_ERR "Trying to free already-free IRQ %d\n", irq); |
06fcb0c6 | 454 | spin_unlock_irqrestore(&desc->lock, flags); |
1da177e4 LT |
455 | return; |
456 | } | |
a304e1b8 DW |
457 | #ifdef CONFIG_DEBUG_SHIRQ |
458 | if (handler) { | |
459 | /* | |
460 | * It's a shared IRQ -- the driver ought to be prepared for it | |
461 | * to happen even now it's being freed, so let's make sure.... | |
462 | * We do this after actually deregistering it, to make sure that | |
463 | * a 'real' IRQ doesn't run in parallel with our fake | |
464 | */ | |
8b7f0715 | 465 | local_irq_save(flags); |
a304e1b8 | 466 | handler(irq, dev_id); |
8b7f0715 | 467 | local_irq_restore(flags); |
a304e1b8 DW |
468 | } |
469 | #endif | |
1da177e4 | 470 | } |
1da177e4 LT |
471 | EXPORT_SYMBOL(free_irq); |
472 | ||
473 | /** | |
474 | * request_irq - allocate an interrupt line | |
475 | * @irq: Interrupt line to allocate | |
476 | * @handler: Function to be called when the IRQ occurs | |
477 | * @irqflags: Interrupt type flags | |
478 | * @devname: An ascii name for the claiming device | |
479 | * @dev_id: A cookie passed back to the handler function | |
480 | * | |
481 | * This call allocates interrupt resources and enables the | |
482 | * interrupt line and IRQ handling. From the point this | |
483 | * call is made your handler function may be invoked. Since | |
484 | * your handler function must clear any interrupt the board | |
485 | * raises, you must take care both to initialise your hardware | |
486 | * and to set up the interrupt handler in the right order. | |
487 | * | |
488 | * Dev_id must be globally unique. Normally the address of the | |
489 | * device data structure is used as the cookie. Since the handler | |
490 | * receives this value it makes sense to use it. | |
491 | * | |
492 | * If your interrupt is shared you must pass a non NULL dev_id | |
493 | * as this is required when freeing the interrupt. | |
494 | * | |
495 | * Flags: | |
496 | * | |
3cca53b0 TG |
497 | * IRQF_SHARED Interrupt is shared |
498 | * IRQF_DISABLED Disable local interrupts while processing | |
499 | * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy | |
1da177e4 LT |
500 | * |
501 | */ | |
da482792 | 502 | int request_irq(unsigned int irq, irq_handler_t handler, |
06fcb0c6 | 503 | unsigned long irqflags, const char *devname, void *dev_id) |
1da177e4 | 504 | { |
06fcb0c6 | 505 | struct irqaction *action; |
1da177e4 LT |
506 | int retval; |
507 | ||
fbb9ce95 IM |
508 | #ifdef CONFIG_LOCKDEP |
509 | /* | |
510 | * Lockdep wants atomic interrupt handlers: | |
511 | */ | |
38515e90 | 512 | irqflags |= IRQF_DISABLED; |
fbb9ce95 | 513 | #endif |
1da177e4 LT |
514 | /* |
515 | * Sanity-check: shared interrupts must pass in a real dev-ID, | |
516 | * otherwise we'll have trouble later trying to figure out | |
517 | * which interrupt is which (messes up the interrupt freeing | |
518 | * logic etc). | |
519 | */ | |
3cca53b0 | 520 | if ((irqflags & IRQF_SHARED) && !dev_id) |
1da177e4 LT |
521 | return -EINVAL; |
522 | if (irq >= NR_IRQS) | |
523 | return -EINVAL; | |
6550c775 TG |
524 | if (irq_desc[irq].status & IRQ_NOREQUEST) |
525 | return -EINVAL; | |
1da177e4 LT |
526 | if (!handler) |
527 | return -EINVAL; | |
528 | ||
529 | action = kmalloc(sizeof(struct irqaction), GFP_ATOMIC); | |
530 | if (!action) | |
531 | return -ENOMEM; | |
532 | ||
533 | action->handler = handler; | |
534 | action->flags = irqflags; | |
535 | cpus_clear(action->mask); | |
536 | action->name = devname; | |
537 | action->next = NULL; | |
538 | action->dev_id = dev_id; | |
539 | ||
eee45269 IK |
540 | select_smp_affinity(irq); |
541 | ||
a304e1b8 DW |
542 | #ifdef CONFIG_DEBUG_SHIRQ |
543 | if (irqflags & IRQF_SHARED) { | |
544 | /* | |
545 | * It's a shared IRQ -- the driver ought to be prepared for it | |
546 | * to happen immediately, so let's make sure.... | |
547 | * We do this before actually registering it, to make sure that | |
548 | * a 'real' IRQ doesn't run in parallel with our fake | |
549 | */ | |
550 | if (irqflags & IRQF_DISABLED) { | |
551 | unsigned long flags; | |
552 | ||
553 | local_irq_save(flags); | |
554 | handler(irq, dev_id); | |
555 | local_irq_restore(flags); | |
556 | } else | |
557 | handler(irq, dev_id); | |
558 | } | |
559 | #endif | |
560 | ||
1da177e4 LT |
561 | retval = setup_irq(irq, action); |
562 | if (retval) | |
563 | kfree(action); | |
564 | ||
565 | return retval; | |
566 | } | |
1da177e4 | 567 | EXPORT_SYMBOL(request_irq); |