2 * linux/kernel/irq/manage.c
4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
5 * Copyright (C) 2005-2006 Thomas Gleixner
7 * This file contains driver APIs to the irq subsystem.
10 #include <linux/irq.h>
11 #include <linux/kthread.h>
12 #include <linux/module.h>
13 #include <linux/random.h>
14 #include <linux/interrupt.h>
15 #include <linux/slab.h>
16 #include <linux/sched.h>
18 #include "internals.h"
21 * synchronize_irq - wait for pending IRQ handlers (on other CPUs)
22 * @irq: interrupt number to wait for
24 * This function waits for any pending IRQ handlers for this interrupt
25 * to complete before returning. If you use this function while
26 * holding a resource the IRQ handler may need you will deadlock.
28 * This function may be called - with care - from IRQ context.
30 void synchronize_irq(unsigned int irq
)
32 struct irq_desc
*desc
= irq_to_desc(irq
);
42 * Wait until we're out of the critical section. This might
43 * give the wrong answer due to the lack of memory barriers.
45 while (desc
->status
& IRQ_INPROGRESS
)
48 /* Ok, that indicated we're done: double-check carefully. */
49 spin_lock_irqsave(&desc
->lock
, flags
);
50 status
= desc
->status
;
51 spin_unlock_irqrestore(&desc
->lock
, flags
);
53 /* Oops, that failed? */
54 } while (status
& IRQ_INPROGRESS
);
57 * We made sure that no hardirq handler is running. Now verify
58 * that no threaded handlers are active.
60 wait_event(desc
->wait_for_threads
, !atomic_read(&desc
->threads_active
));
62 EXPORT_SYMBOL(synchronize_irq
);
65 cpumask_var_t irq_default_affinity
;
68 * irq_can_set_affinity - Check if the affinity of a given irq can be set
69 * @irq: Interrupt to check
72 int irq_can_set_affinity(unsigned int irq
)
74 struct irq_desc
*desc
= irq_to_desc(irq
);
76 if (CHECK_IRQ_PER_CPU(desc
->status
) || !desc
->chip
||
77 !desc
->chip
->set_affinity
)
84 irq_set_thread_affinity(struct irq_desc
*desc
, const struct cpumask
*cpumask
)
86 struct irqaction
*action
= desc
->action
;
90 set_cpus_allowed_ptr(action
->thread
, cpumask
);
91 action
= action
->next
;
96 * irq_set_affinity - Set the irq affinity of a given irq
97 * @irq: Interrupt to set affinity
101 int irq_set_affinity(unsigned int irq
, const struct cpumask
*cpumask
)
103 struct irq_desc
*desc
= irq_to_desc(irq
);
106 if (!desc
->chip
->set_affinity
)
109 spin_lock_irqsave(&desc
->lock
, flags
);
111 #ifdef CONFIG_GENERIC_PENDING_IRQ
112 if (desc
->status
& IRQ_MOVE_PCNTXT
|| desc
->status
& IRQ_DISABLED
) {
113 cpumask_copy(desc
->affinity
, cpumask
);
114 desc
->chip
->set_affinity(irq
, cpumask
);
116 desc
->status
|= IRQ_MOVE_PENDING
;
117 cpumask_copy(desc
->pending_mask
, cpumask
);
120 cpumask_copy(desc
->affinity
, cpumask
);
121 desc
->chip
->set_affinity(irq
, cpumask
);
123 irq_set_thread_affinity(desc
, cpumask
);
124 desc
->status
|= IRQ_AFFINITY_SET
;
125 spin_unlock_irqrestore(&desc
->lock
, flags
);
129 #ifndef CONFIG_AUTO_IRQ_AFFINITY
131 * Generic version of the affinity autoselector.
133 static int setup_affinity(unsigned int irq
, struct irq_desc
*desc
)
135 if (!irq_can_set_affinity(irq
))
139 * Preserve an userspace affinity setup, but make sure that
140 * one of the targets is online.
142 if (desc
->status
& (IRQ_AFFINITY_SET
| IRQ_NO_BALANCING
)) {
143 if (cpumask_any_and(desc
->affinity
, cpu_online_mask
)
147 desc
->status
&= ~IRQ_AFFINITY_SET
;
150 cpumask_and(desc
->affinity
, cpu_online_mask
, irq_default_affinity
);
152 desc
->chip
->set_affinity(irq
, desc
->affinity
);
157 static inline int setup_affinity(unsigned int irq
, struct irq_desc
*d
)
159 return irq_select_affinity(irq
);
164 * Called when affinity is set via /proc/irq
166 int irq_select_affinity_usr(unsigned int irq
)
168 struct irq_desc
*desc
= irq_to_desc(irq
);
172 spin_lock_irqsave(&desc
->lock
, flags
);
173 ret
= setup_affinity(irq
, desc
);
175 irq_set_thread_affinity(desc
, desc
->affinity
);
176 spin_unlock_irqrestore(&desc
->lock
, flags
);
182 static inline int setup_affinity(unsigned int irq
, struct irq_desc
*desc
)
189 * disable_irq_nosync - disable an irq without waiting
190 * @irq: Interrupt to disable
192 * Disable the selected interrupt line. Disables and Enables are
194 * Unlike disable_irq(), this function does not ensure existing
195 * instances of the IRQ handler have completed before returning.
197 * This function may be called from IRQ context.
199 void disable_irq_nosync(unsigned int irq
)
201 struct irq_desc
*desc
= irq_to_desc(irq
);
207 spin_lock_irqsave(&desc
->lock
, flags
);
208 if (!desc
->depth
++) {
209 desc
->status
|= IRQ_DISABLED
;
210 desc
->chip
->disable(irq
);
212 spin_unlock_irqrestore(&desc
->lock
, flags
);
214 EXPORT_SYMBOL(disable_irq_nosync
);
217 * disable_irq - disable an irq and wait for completion
218 * @irq: Interrupt to disable
220 * Disable the selected interrupt line. Enables and Disables are
222 * This function waits for any pending IRQ handlers for this interrupt
223 * to complete before returning. If you use this function while
224 * holding a resource the IRQ handler may need you will deadlock.
226 * This function may be called - with care - from IRQ context.
228 void disable_irq(unsigned int irq
)
230 struct irq_desc
*desc
= irq_to_desc(irq
);
235 disable_irq_nosync(irq
);
237 synchronize_irq(irq
);
239 EXPORT_SYMBOL(disable_irq
);
241 static void __enable_irq(struct irq_desc
*desc
, unsigned int irq
)
243 switch (desc
->depth
) {
245 WARN(1, KERN_WARNING
"Unbalanced enable for IRQ %d\n", irq
);
248 unsigned int status
= desc
->status
& ~IRQ_DISABLED
;
250 /* Prevent probing on this irq: */
251 desc
->status
= status
| IRQ_NOPROBE
;
252 check_irq_resend(desc
, irq
);
261 * enable_irq - enable handling of an irq
262 * @irq: Interrupt to enable
264 * Undoes the effect of one call to disable_irq(). If this
265 * matches the last disable, processing of interrupts on this
266 * IRQ line is re-enabled.
268 * This function may be called from IRQ context.
270 void enable_irq(unsigned int irq
)
272 struct irq_desc
*desc
= irq_to_desc(irq
);
278 spin_lock_irqsave(&desc
->lock
, flags
);
279 __enable_irq(desc
, irq
);
280 spin_unlock_irqrestore(&desc
->lock
, flags
);
282 EXPORT_SYMBOL(enable_irq
);
284 static int set_irq_wake_real(unsigned int irq
, unsigned int on
)
286 struct irq_desc
*desc
= irq_to_desc(irq
);
289 if (desc
->chip
->set_wake
)
290 ret
= desc
->chip
->set_wake(irq
, on
);
296 * set_irq_wake - control irq power management wakeup
297 * @irq: interrupt to control
298 * @on: enable/disable power management wakeup
300 * Enable/disable power management wakeup mode, which is
301 * disabled by default. Enables and disables must match,
302 * just as they match for non-wakeup mode support.
304 * Wakeup mode lets this IRQ wake the system from sleep
305 * states like "suspend to RAM".
307 int set_irq_wake(unsigned int irq
, unsigned int on
)
309 struct irq_desc
*desc
= irq_to_desc(irq
);
313 /* wakeup-capable irqs can be shared between drivers that
314 * don't need to have the same sleep mode behaviors.
316 spin_lock_irqsave(&desc
->lock
, flags
);
318 if (desc
->wake_depth
++ == 0) {
319 ret
= set_irq_wake_real(irq
, on
);
321 desc
->wake_depth
= 0;
323 desc
->status
|= IRQ_WAKEUP
;
326 if (desc
->wake_depth
== 0) {
327 WARN(1, "Unbalanced IRQ %d wake disable\n", irq
);
328 } else if (--desc
->wake_depth
== 0) {
329 ret
= set_irq_wake_real(irq
, on
);
331 desc
->wake_depth
= 1;
333 desc
->status
&= ~IRQ_WAKEUP
;
337 spin_unlock_irqrestore(&desc
->lock
, flags
);
340 EXPORT_SYMBOL(set_irq_wake
);
343 * Internal function that tells the architecture code whether a
344 * particular irq has been exclusively allocated or is available
347 int can_request_irq(unsigned int irq
, unsigned long irqflags
)
349 struct irq_desc
*desc
= irq_to_desc(irq
);
350 struct irqaction
*action
;
355 if (desc
->status
& IRQ_NOREQUEST
)
358 action
= desc
->action
;
360 if (irqflags
& action
->flags
& IRQF_SHARED
)
366 void compat_irq_chip_set_default_handler(struct irq_desc
*desc
)
369 * If the architecture still has not overriden
370 * the flow handler then zap the default. This
371 * should catch incorrect flow-type setting.
373 if (desc
->handle_irq
== &handle_bad_irq
)
374 desc
->handle_irq
= NULL
;
377 int __irq_set_trigger(struct irq_desc
*desc
, unsigned int irq
,
381 struct irq_chip
*chip
= desc
->chip
;
383 if (!chip
|| !chip
->set_type
) {
385 * IRQF_TRIGGER_* but the PIC does not support multiple
388 pr_debug("No set_type function for IRQ %d (%s)\n", irq
,
389 chip
? (chip
->name
? : "unknown") : "unknown");
393 /* caller masked out all except trigger mode flags */
394 ret
= chip
->set_type(irq
, flags
);
397 pr_err("setting trigger mode %d for irq %u failed (%pF)\n",
398 (int)flags
, irq
, chip
->set_type
);
400 if (flags
& (IRQ_TYPE_LEVEL_LOW
| IRQ_TYPE_LEVEL_HIGH
))
402 /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */
403 desc
->status
&= ~(IRQ_LEVEL
| IRQ_TYPE_SENSE_MASK
);
404 desc
->status
|= flags
;
410 static inline int irq_thread_should_run(struct irqaction
*action
)
412 return test_and_clear_bit(IRQTF_RUNTHREAD
, &action
->thread_flags
);
415 static int irq_wait_for_interrupt(struct irqaction
*action
)
417 while (!kthread_should_stop()) {
418 set_current_state(TASK_INTERRUPTIBLE
);
419 if (irq_thread_should_run(action
)) {
420 __set_current_state(TASK_RUNNING
);
429 * Interrupt handler thread
431 static int irq_thread(void *data
)
433 struct sched_param param
= { .sched_priority
= MAX_USER_RT_PRIO
/2, };
434 struct irqaction
*action
= data
;
435 struct irq_desc
*desc
= irq_to_desc(action
->irq
);
438 sched_setscheduler(current
, SCHED_FIFO
, ¶m
);
439 current
->irqaction
= action
;
441 while (!irq_wait_for_interrupt(action
)) {
443 atomic_inc(&desc
->threads_active
);
445 spin_lock_irq(&desc
->lock
);
446 if (unlikely(desc
->status
& IRQ_DISABLED
)) {
448 * CHECKME: We might need a dedicated
449 * IRQ_THREAD_PENDING flag here, which
450 * retriggers the thread in check_irq_resend()
451 * but AFAICT IRQ_PENDING should be fine as it
452 * retriggers the interrupt itself --- tglx
454 desc
->status
|= IRQ_PENDING
;
455 spin_unlock_irq(&desc
->lock
);
457 spin_unlock_irq(&desc
->lock
);
459 action
->thread_fn(action
->irq
, action
->dev_id
);
462 wake
= atomic_dec_and_test(&desc
->threads_active
);
464 if (wake
&& waitqueue_active(&desc
->wait_for_threads
))
465 wake_up(&desc
->wait_for_threads
);
469 * Clear irqaction. Otherwise exit_irq_thread() would make
470 * fuzz about an active irq thread going into nirvana.
472 current
->irqaction
= NULL
;
477 * Called from do_exit()
479 void exit_irq_thread(void)
481 struct task_struct
*tsk
= current
;
487 "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
488 tsk
->comm
? tsk
->comm
: "", tsk
->pid
, tsk
->irqaction
->irq
);
491 * Set the THREAD DIED flag to prevent further wakeups of the
492 * soon to be gone threaded handler.
494 set_bit(IRQTF_DIED
, &tsk
->irqaction
->flags
);
498 * Internal function to register an irqaction - typically used to
499 * allocate special interrupts that are part of the architecture.
502 __setup_irq(unsigned int irq
, struct irq_desc
*desc
, struct irqaction
*new)
504 struct irqaction
*old
, **old_ptr
;
505 const char *old_name
= NULL
;
513 if (desc
->chip
== &no_irq_chip
)
516 * Some drivers like serial.c use request_irq() heavily,
517 * so we have to be careful not to interfere with a
520 if (new->flags
& IRQF_SAMPLE_RANDOM
) {
522 * This function might sleep, we want to call it first,
523 * outside of the atomic block.
524 * Yes, this might clear the entropy pool if the wrong
525 * driver is attempted to be loaded, without actually
526 * installing a new handler, but is this really a problem,
527 * only the sysadmin is able to do this.
529 rand_initialize_irq(irq
);
535 if (new->thread_fn
) {
536 struct task_struct
*t
;
538 t
= kthread_create(irq_thread
, new, "irq/%d-%s", irq
,
543 * We keep the reference to the task struct even if
544 * the thread dies to avoid that the interrupt code
545 * references an already freed task_struct.
553 * The following block of code has to be executed atomically
555 spin_lock_irqsave(&desc
->lock
, flags
);
556 old_ptr
= &desc
->action
;
560 * Can't share interrupts unless both agree to and are
561 * the same type (level, edge, polarity). So both flag
562 * fields must have IRQF_SHARED set and the bits which
563 * set the trigger type must match.
565 if (!((old
->flags
& new->flags
) & IRQF_SHARED
) ||
566 ((old
->flags
^ new->flags
) & IRQF_TRIGGER_MASK
)) {
567 old_name
= old
->name
;
571 #if defined(CONFIG_IRQ_PER_CPU)
572 /* All handlers must agree on per-cpuness */
573 if ((old
->flags
& IRQF_PERCPU
) !=
574 (new->flags
& IRQF_PERCPU
))
578 /* add new interrupt at end of irq queue */
580 old_ptr
= &old
->next
;
587 irq_chip_set_defaults(desc
->chip
);
589 init_waitqueue_head(&desc
->wait_for_threads
);
591 /* Setup the type (level, edge polarity) if configured: */
592 if (new->flags
& IRQF_TRIGGER_MASK
) {
593 ret
= __irq_set_trigger(desc
, irq
,
594 new->flags
& IRQF_TRIGGER_MASK
);
599 compat_irq_chip_set_default_handler(desc
);
600 #if defined(CONFIG_IRQ_PER_CPU)
601 if (new->flags
& IRQF_PERCPU
)
602 desc
->status
|= IRQ_PER_CPU
;
605 desc
->status
&= ~(IRQ_AUTODETECT
| IRQ_WAITING
|
606 IRQ_INPROGRESS
| IRQ_SPURIOUS_DISABLED
);
608 if (!(desc
->status
& IRQ_NOAUTOEN
)) {
610 desc
->status
&= ~IRQ_DISABLED
;
611 desc
->chip
->startup(irq
);
613 /* Undo nested disables: */
616 /* Exclude IRQ from balancing if requested */
617 if (new->flags
& IRQF_NOBALANCING
)
618 desc
->status
|= IRQ_NO_BALANCING
;
620 /* Set default affinity mask once everything is setup */
621 setup_affinity(irq
, desc
);
623 } else if ((new->flags
& IRQF_TRIGGER_MASK
)
624 && (new->flags
& IRQF_TRIGGER_MASK
)
625 != (desc
->status
& IRQ_TYPE_SENSE_MASK
)) {
626 /* hope the handler works with the actual trigger mode... */
627 pr_warning("IRQ %d uses trigger mode %d; requested %d\n",
628 irq
, (int)(desc
->status
& IRQ_TYPE_SENSE_MASK
),
629 (int)(new->flags
& IRQF_TRIGGER_MASK
));
634 /* Reset broken irq detection when installing new handler */
636 desc
->irqs_unhandled
= 0;
639 * Check whether we disabled the irq via the spurious handler
640 * before. Reenable it and give it another chance.
642 if (shared
&& (desc
->status
& IRQ_SPURIOUS_DISABLED
)) {
643 desc
->status
&= ~IRQ_SPURIOUS_DISABLED
;
644 __enable_irq(desc
, irq
);
647 spin_unlock_irqrestore(&desc
->lock
, flags
);
650 register_irq_proc(irq
, desc
);
652 register_handler_proc(irq
, new);
657 #ifdef CONFIG_DEBUG_SHIRQ
658 if (!(new->flags
& IRQF_PROBE_SHARED
)) {
659 printk(KERN_ERR
"IRQ handler type mismatch for IRQ %d\n", irq
);
661 printk(KERN_ERR
"current handler: %s\n", old_name
);
668 spin_unlock_irqrestore(&desc
->lock
, flags
);
670 struct task_struct
*t
= new->thread
;
673 if (likely(!test_bit(IRQTF_DIED
, &new->thread_flags
)))
681 * setup_irq - setup an interrupt
682 * @irq: Interrupt line to setup
683 * @act: irqaction for the interrupt
685 * Used to statically setup interrupts in the early boot process.
687 int setup_irq(unsigned int irq
, struct irqaction
*act
)
689 struct irq_desc
*desc
= irq_to_desc(irq
);
691 return __setup_irq(irq
, desc
, act
);
693 EXPORT_SYMBOL_GPL(setup_irq
);
696 * Internal function to unregister an irqaction - used to free
697 * regular and special interrupts that are part of the architecture.
699 static struct irqaction
*__free_irq(unsigned int irq
, void *dev_id
)
701 struct irq_desc
*desc
= irq_to_desc(irq
);
702 struct irqaction
*action
, **action_ptr
;
703 struct task_struct
*irqthread
;
706 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
711 spin_lock_irqsave(&desc
->lock
, flags
);
714 * There can be multiple actions per IRQ descriptor, find the right
715 * one based on the dev_id:
717 action_ptr
= &desc
->action
;
719 action
= *action_ptr
;
722 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
723 spin_unlock_irqrestore(&desc
->lock
, flags
);
728 if (action
->dev_id
== dev_id
)
730 action_ptr
= &action
->next
;
733 /* Found it - now remove it from the list of entries: */
734 *action_ptr
= action
->next
;
736 /* Currently used only by UML, might disappear one day: */
737 #ifdef CONFIG_IRQ_RELEASE_METHOD
738 if (desc
->chip
->release
)
739 desc
->chip
->release(irq
, dev_id
);
742 /* If this was the last handler, shut down the IRQ line: */
744 desc
->status
|= IRQ_DISABLED
;
745 if (desc
->chip
->shutdown
)
746 desc
->chip
->shutdown(irq
);
748 desc
->chip
->disable(irq
);
751 irqthread
= action
->thread
;
752 action
->thread
= NULL
;
754 spin_unlock_irqrestore(&desc
->lock
, flags
);
756 unregister_handler_proc(irq
, action
);
758 /* Make sure it's not being used on another CPU: */
759 synchronize_irq(irq
);
762 if (!test_bit(IRQTF_DIED
, &action
->thread_flags
))
763 kthread_stop(irqthread
);
764 put_task_struct(irqthread
);
767 #ifdef CONFIG_DEBUG_SHIRQ
769 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
770 * event to happen even now it's being freed, so let's make sure that
771 * is so by doing an extra call to the handler ....
773 * ( We do this after actually deregistering it, to make sure that a
774 * 'real' IRQ doesn't run in * parallel with our fake. )
776 if (action
->flags
& IRQF_SHARED
) {
777 local_irq_save(flags
);
778 action
->handler(irq
, dev_id
);
779 local_irq_restore(flags
);
786 * remove_irq - free an interrupt
787 * @irq: Interrupt line to free
788 * @act: irqaction for the interrupt
790 * Used to remove interrupts statically setup by the early boot process.
792 void remove_irq(unsigned int irq
, struct irqaction
*act
)
794 __free_irq(irq
, act
->dev_id
);
796 EXPORT_SYMBOL_GPL(remove_irq
);
799 * free_irq - free an interrupt allocated with request_irq
800 * @irq: Interrupt line to free
801 * @dev_id: Device identity to free
803 * Remove an interrupt handler. The handler is removed and if the
804 * interrupt line is no longer in use by any driver it is disabled.
805 * On a shared IRQ the caller must ensure the interrupt is disabled
806 * on the card it drives before calling this function. The function
807 * does not return until any executing interrupts for this IRQ
810 * This function must not be called from interrupt context.
812 void free_irq(unsigned int irq
, void *dev_id
)
814 kfree(__free_irq(irq
, dev_id
));
816 EXPORT_SYMBOL(free_irq
);
819 * request_threaded_irq - allocate an interrupt line
820 * @irq: Interrupt line to allocate
821 * @handler: Function to be called when the IRQ occurs.
822 * Primary handler for threaded interrupts
823 * @thread_fn: Function called from the irq handler thread
824 * If NULL, no irq thread is created
825 * @irqflags: Interrupt type flags
826 * @devname: An ascii name for the claiming device
827 * @dev_id: A cookie passed back to the handler function
829 * This call allocates interrupt resources and enables the
830 * interrupt line and IRQ handling. From the point this
831 * call is made your handler function may be invoked. Since
832 * your handler function must clear any interrupt the board
833 * raises, you must take care both to initialise your hardware
834 * and to set up the interrupt handler in the right order.
836 * If you want to set up a threaded irq handler for your device
837 * then you need to supply @handler and @thread_fn. @handler ist
838 * still called in hard interrupt context and has to check
839 * whether the interrupt originates from the device. If yes it
840 * needs to disable the interrupt on the device and return
841 * IRQ_THREAD_WAKE which will wake up the handler thread and run
842 * @thread_fn. This split handler design is necessary to support
845 * Dev_id must be globally unique. Normally the address of the
846 * device data structure is used as the cookie. Since the handler
847 * receives this value it makes sense to use it.
849 * If your interrupt is shared you must pass a non NULL dev_id
850 * as this is required when freeing the interrupt.
854 * IRQF_SHARED Interrupt is shared
855 * IRQF_DISABLED Disable local interrupts while processing
856 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
857 * IRQF_TRIGGER_* Specify active edge(s) or level
860 int request_threaded_irq(unsigned int irq
, irq_handler_t handler
,
861 irq_handler_t thread_fn
, unsigned long irqflags
,
862 const char *devname
, void *dev_id
)
864 struct irqaction
*action
;
865 struct irq_desc
*desc
;
869 * handle_IRQ_event() always ignores IRQF_DISABLED except for
870 * the _first_ irqaction (sigh). That can cause oopsing, but
871 * the behavior is classified as "will not fix" so we need to
872 * start nudging drivers away from using that idiom.
874 if ((irqflags
& (IRQF_SHARED
|IRQF_DISABLED
)) ==
875 (IRQF_SHARED
|IRQF_DISABLED
)) {
877 "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n",
881 #ifdef CONFIG_LOCKDEP
883 * Lockdep wants atomic interrupt handlers:
885 irqflags
|= IRQF_DISABLED
;
888 * Sanity-check: shared interrupts must pass in a real dev-ID,
889 * otherwise we'll have trouble later trying to figure out
890 * which interrupt is which (messes up the interrupt freeing
893 if ((irqflags
& IRQF_SHARED
) && !dev_id
)
896 desc
= irq_to_desc(irq
);
900 if (desc
->status
& IRQ_NOREQUEST
)
905 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
909 action
->handler
= handler
;
910 action
->thread_fn
= thread_fn
;
911 action
->flags
= irqflags
;
912 action
->name
= devname
;
913 action
->dev_id
= dev_id
;
915 retval
= __setup_irq(irq
, desc
, action
);
919 #ifdef CONFIG_DEBUG_SHIRQ
920 if (irqflags
& IRQF_SHARED
) {
922 * It's a shared IRQ -- the driver ought to be prepared for it
923 * to happen immediately, so let's make sure....
924 * We disable the irq to make sure that a 'real' IRQ doesn't
925 * run in parallel with our fake.
930 local_irq_save(flags
);
932 handler(irq
, dev_id
);
934 local_irq_restore(flags
);
940 EXPORT_SYMBOL(request_threaded_irq
);