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
)
113 desc
->chip
->set_affinity(irq
, cpumask
);
115 desc
->status
|= IRQ_MOVE_PENDING
;
116 cpumask_copy(desc
->pending_mask
, cpumask
);
119 cpumask_copy(desc
->affinity
, cpumask
);
120 desc
->chip
->set_affinity(irq
, cpumask
);
122 irq_set_thread_affinity(desc
, cpumask
);
123 desc
->status
|= IRQ_AFFINITY_SET
;
124 spin_unlock_irqrestore(&desc
->lock
, flags
);
128 #ifndef CONFIG_AUTO_IRQ_AFFINITY
130 * Generic version of the affinity autoselector.
132 static int setup_affinity(unsigned int irq
, struct irq_desc
*desc
)
134 if (!irq_can_set_affinity(irq
))
138 * Preserve an userspace affinity setup, but make sure that
139 * one of the targets is online.
141 if (desc
->status
& (IRQ_AFFINITY_SET
| IRQ_NO_BALANCING
)) {
142 if (cpumask_any_and(desc
->affinity
, cpu_online_mask
)
146 desc
->status
&= ~IRQ_AFFINITY_SET
;
149 cpumask_and(desc
->affinity
, cpu_online_mask
, irq_default_affinity
);
151 desc
->chip
->set_affinity(irq
, desc
->affinity
);
156 static inline int setup_affinity(unsigned int irq
, struct irq_desc
*d
)
158 return irq_select_affinity(irq
);
163 * Called when affinity is set via /proc/irq
165 int irq_select_affinity_usr(unsigned int irq
)
167 struct irq_desc
*desc
= irq_to_desc(irq
);
171 spin_lock_irqsave(&desc
->lock
, flags
);
172 ret
= setup_affinity(irq
, desc
);
174 irq_set_thread_affinity(desc
, desc
->affinity
);
175 spin_unlock_irqrestore(&desc
->lock
, flags
);
181 static inline int setup_affinity(unsigned int irq
, struct irq_desc
*desc
)
187 void __disable_irq(struct irq_desc
*desc
, unsigned int irq
, bool suspend
)
190 if (!desc
->action
|| (desc
->action
->flags
& IRQF_TIMER
))
192 desc
->status
|= IRQ_SUSPENDED
;
195 if (!desc
->depth
++) {
196 desc
->status
|= IRQ_DISABLED
;
197 desc
->chip
->disable(irq
);
202 * disable_irq_nosync - disable an irq without waiting
203 * @irq: Interrupt to disable
205 * Disable the selected interrupt line. Disables and Enables are
207 * Unlike disable_irq(), this function does not ensure existing
208 * instances of the IRQ handler have completed before returning.
210 * This function may be called from IRQ context.
212 void disable_irq_nosync(unsigned int irq
)
214 struct irq_desc
*desc
= irq_to_desc(irq
);
220 spin_lock_irqsave(&desc
->lock
, flags
);
221 __disable_irq(desc
, irq
, false);
222 spin_unlock_irqrestore(&desc
->lock
, flags
);
224 EXPORT_SYMBOL(disable_irq_nosync
);
227 * disable_irq - disable an irq and wait for completion
228 * @irq: Interrupt to disable
230 * Disable the selected interrupt line. Enables and Disables are
232 * This function waits for any pending IRQ handlers for this interrupt
233 * to complete before returning. If you use this function while
234 * holding a resource the IRQ handler may need you will deadlock.
236 * This function may be called - with care - from IRQ context.
238 void disable_irq(unsigned int irq
)
240 struct irq_desc
*desc
= irq_to_desc(irq
);
245 disable_irq_nosync(irq
);
247 synchronize_irq(irq
);
249 EXPORT_SYMBOL(disable_irq
);
251 void __enable_irq(struct irq_desc
*desc
, unsigned int irq
, bool resume
)
254 desc
->status
&= ~IRQ_SUSPENDED
;
256 switch (desc
->depth
) {
259 WARN(1, KERN_WARNING
"Unbalanced enable for IRQ %d\n", irq
);
262 unsigned int status
= desc
->status
& ~IRQ_DISABLED
;
264 if (desc
->status
& IRQ_SUSPENDED
)
266 /* Prevent probing on this irq: */
267 desc
->status
= status
| IRQ_NOPROBE
;
268 check_irq_resend(desc
, irq
);
277 * enable_irq - enable handling of an irq
278 * @irq: Interrupt to enable
280 * Undoes the effect of one call to disable_irq(). If this
281 * matches the last disable, processing of interrupts on this
282 * IRQ line is re-enabled.
284 * This function may be called from IRQ context.
286 void enable_irq(unsigned int irq
)
288 struct irq_desc
*desc
= irq_to_desc(irq
);
294 spin_lock_irqsave(&desc
->lock
, flags
);
295 __enable_irq(desc
, irq
, false);
296 spin_unlock_irqrestore(&desc
->lock
, flags
);
298 EXPORT_SYMBOL(enable_irq
);
300 static int set_irq_wake_real(unsigned int irq
, unsigned int on
)
302 struct irq_desc
*desc
= irq_to_desc(irq
);
305 if (desc
->chip
->set_wake
)
306 ret
= desc
->chip
->set_wake(irq
, on
);
312 * set_irq_wake - control irq power management wakeup
313 * @irq: interrupt to control
314 * @on: enable/disable power management wakeup
316 * Enable/disable power management wakeup mode, which is
317 * disabled by default. Enables and disables must match,
318 * just as they match for non-wakeup mode support.
320 * Wakeup mode lets this IRQ wake the system from sleep
321 * states like "suspend to RAM".
323 int set_irq_wake(unsigned int irq
, unsigned int on
)
325 struct irq_desc
*desc
= irq_to_desc(irq
);
329 /* wakeup-capable irqs can be shared between drivers that
330 * don't need to have the same sleep mode behaviors.
332 spin_lock_irqsave(&desc
->lock
, flags
);
334 if (desc
->wake_depth
++ == 0) {
335 ret
= set_irq_wake_real(irq
, on
);
337 desc
->wake_depth
= 0;
339 desc
->status
|= IRQ_WAKEUP
;
342 if (desc
->wake_depth
== 0) {
343 WARN(1, "Unbalanced IRQ %d wake disable\n", irq
);
344 } else if (--desc
->wake_depth
== 0) {
345 ret
= set_irq_wake_real(irq
, on
);
347 desc
->wake_depth
= 1;
349 desc
->status
&= ~IRQ_WAKEUP
;
353 spin_unlock_irqrestore(&desc
->lock
, flags
);
356 EXPORT_SYMBOL(set_irq_wake
);
359 * Internal function that tells the architecture code whether a
360 * particular irq has been exclusively allocated or is available
363 int can_request_irq(unsigned int irq
, unsigned long irqflags
)
365 struct irq_desc
*desc
= irq_to_desc(irq
);
366 struct irqaction
*action
;
371 if (desc
->status
& IRQ_NOREQUEST
)
374 action
= desc
->action
;
376 if (irqflags
& action
->flags
& IRQF_SHARED
)
382 void compat_irq_chip_set_default_handler(struct irq_desc
*desc
)
385 * If the architecture still has not overriden
386 * the flow handler then zap the default. This
387 * should catch incorrect flow-type setting.
389 if (desc
->handle_irq
== &handle_bad_irq
)
390 desc
->handle_irq
= NULL
;
393 int __irq_set_trigger(struct irq_desc
*desc
, unsigned int irq
,
397 struct irq_chip
*chip
= desc
->chip
;
399 if (!chip
|| !chip
->set_type
) {
401 * IRQF_TRIGGER_* but the PIC does not support multiple
404 pr_debug("No set_type function for IRQ %d (%s)\n", irq
,
405 chip
? (chip
->name
? : "unknown") : "unknown");
409 /* caller masked out all except trigger mode flags */
410 ret
= chip
->set_type(irq
, flags
);
413 pr_err("setting trigger mode %d for irq %u failed (%pF)\n",
414 (int)flags
, irq
, chip
->set_type
);
416 if (flags
& (IRQ_TYPE_LEVEL_LOW
| IRQ_TYPE_LEVEL_HIGH
))
418 /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */
419 desc
->status
&= ~(IRQ_LEVEL
| IRQ_TYPE_SENSE_MASK
);
420 desc
->status
|= flags
;
426 static int irq_wait_for_interrupt(struct irqaction
*action
)
428 while (!kthread_should_stop()) {
429 set_current_state(TASK_INTERRUPTIBLE
);
431 if (test_and_clear_bit(IRQTF_RUNTHREAD
,
432 &action
->thread_flags
)) {
433 __set_current_state(TASK_RUNNING
);
442 * Interrupt handler thread
444 static int irq_thread(void *data
)
446 struct sched_param param
= { .sched_priority
= MAX_USER_RT_PRIO
/2, };
447 struct irqaction
*action
= data
;
448 struct irq_desc
*desc
= irq_to_desc(action
->irq
);
451 sched_setscheduler(current
, SCHED_FIFO
, ¶m
);
452 current
->irqaction
= action
;
454 while (!irq_wait_for_interrupt(action
)) {
456 atomic_inc(&desc
->threads_active
);
458 spin_lock_irq(&desc
->lock
);
459 if (unlikely(desc
->status
& IRQ_DISABLED
)) {
461 * CHECKME: We might need a dedicated
462 * IRQ_THREAD_PENDING flag here, which
463 * retriggers the thread in check_irq_resend()
464 * but AFAICT IRQ_PENDING should be fine as it
465 * retriggers the interrupt itself --- tglx
467 desc
->status
|= IRQ_PENDING
;
468 spin_unlock_irq(&desc
->lock
);
470 spin_unlock_irq(&desc
->lock
);
472 action
->thread_fn(action
->irq
, action
->dev_id
);
475 wake
= atomic_dec_and_test(&desc
->threads_active
);
477 if (wake
&& waitqueue_active(&desc
->wait_for_threads
))
478 wake_up(&desc
->wait_for_threads
);
482 * Clear irqaction. Otherwise exit_irq_thread() would make
483 * fuzz about an active irq thread going into nirvana.
485 current
->irqaction
= NULL
;
490 * Called from do_exit()
492 void exit_irq_thread(void)
494 struct task_struct
*tsk
= current
;
500 "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
501 tsk
->comm
? tsk
->comm
: "", tsk
->pid
, tsk
->irqaction
->irq
);
504 * Set the THREAD DIED flag to prevent further wakeups of the
505 * soon to be gone threaded handler.
507 set_bit(IRQTF_DIED
, &tsk
->irqaction
->flags
);
511 * Internal function to register an irqaction - typically used to
512 * allocate special interrupts that are part of the architecture.
515 __setup_irq(unsigned int irq
, struct irq_desc
*desc
, struct irqaction
*new)
517 struct irqaction
*old
, **old_ptr
;
518 const char *old_name
= NULL
;
526 if (desc
->chip
== &no_irq_chip
)
529 * Some drivers like serial.c use request_irq() heavily,
530 * so we have to be careful not to interfere with a
533 if (new->flags
& IRQF_SAMPLE_RANDOM
) {
535 * This function might sleep, we want to call it first,
536 * outside of the atomic block.
537 * Yes, this might clear the entropy pool if the wrong
538 * driver is attempted to be loaded, without actually
539 * installing a new handler, but is this really a problem,
540 * only the sysadmin is able to do this.
542 rand_initialize_irq(irq
);
548 if (new->thread_fn
) {
549 struct task_struct
*t
;
551 t
= kthread_create(irq_thread
, new, "irq/%d-%s", irq
,
556 * We keep the reference to the task struct even if
557 * the thread dies to avoid that the interrupt code
558 * references an already freed task_struct.
566 * The following block of code has to be executed atomically
568 spin_lock_irqsave(&desc
->lock
, flags
);
569 old_ptr
= &desc
->action
;
573 * Can't share interrupts unless both agree to and are
574 * the same type (level, edge, polarity). So both flag
575 * fields must have IRQF_SHARED set and the bits which
576 * set the trigger type must match.
578 if (!((old
->flags
& new->flags
) & IRQF_SHARED
) ||
579 ((old
->flags
^ new->flags
) & IRQF_TRIGGER_MASK
)) {
580 old_name
= old
->name
;
584 #if defined(CONFIG_IRQ_PER_CPU)
585 /* All handlers must agree on per-cpuness */
586 if ((old
->flags
& IRQF_PERCPU
) !=
587 (new->flags
& IRQF_PERCPU
))
591 /* add new interrupt at end of irq queue */
593 old_ptr
= &old
->next
;
600 irq_chip_set_defaults(desc
->chip
);
602 init_waitqueue_head(&desc
->wait_for_threads
);
604 /* Setup the type (level, edge polarity) if configured: */
605 if (new->flags
& IRQF_TRIGGER_MASK
) {
606 ret
= __irq_set_trigger(desc
, irq
,
607 new->flags
& IRQF_TRIGGER_MASK
);
612 compat_irq_chip_set_default_handler(desc
);
613 #if defined(CONFIG_IRQ_PER_CPU)
614 if (new->flags
& IRQF_PERCPU
)
615 desc
->status
|= IRQ_PER_CPU
;
618 desc
->status
&= ~(IRQ_AUTODETECT
| IRQ_WAITING
|
619 IRQ_INPROGRESS
| IRQ_SPURIOUS_DISABLED
);
621 if (!(desc
->status
& IRQ_NOAUTOEN
)) {
623 desc
->status
&= ~IRQ_DISABLED
;
624 desc
->chip
->startup(irq
);
626 /* Undo nested disables: */
629 /* Exclude IRQ from balancing if requested */
630 if (new->flags
& IRQF_NOBALANCING
)
631 desc
->status
|= IRQ_NO_BALANCING
;
633 /* Set default affinity mask once everything is setup */
634 setup_affinity(irq
, desc
);
636 } else if ((new->flags
& IRQF_TRIGGER_MASK
)
637 && (new->flags
& IRQF_TRIGGER_MASK
)
638 != (desc
->status
& IRQ_TYPE_SENSE_MASK
)) {
639 /* hope the handler works with the actual trigger mode... */
640 pr_warning("IRQ %d uses trigger mode %d; requested %d\n",
641 irq
, (int)(desc
->status
& IRQ_TYPE_SENSE_MASK
),
642 (int)(new->flags
& IRQF_TRIGGER_MASK
));
647 /* Reset broken irq detection when installing new handler */
649 desc
->irqs_unhandled
= 0;
652 * Check whether we disabled the irq via the spurious handler
653 * before. Reenable it and give it another chance.
655 if (shared
&& (desc
->status
& IRQ_SPURIOUS_DISABLED
)) {
656 desc
->status
&= ~IRQ_SPURIOUS_DISABLED
;
657 __enable_irq(desc
, irq
, false);
660 spin_unlock_irqrestore(&desc
->lock
, flags
);
663 register_irq_proc(irq
, desc
);
665 register_handler_proc(irq
, new);
670 #ifdef CONFIG_DEBUG_SHIRQ
671 if (!(new->flags
& IRQF_PROBE_SHARED
)) {
672 printk(KERN_ERR
"IRQ handler type mismatch for IRQ %d\n", irq
);
674 printk(KERN_ERR
"current handler: %s\n", old_name
);
681 spin_unlock_irqrestore(&desc
->lock
, flags
);
683 struct task_struct
*t
= new->thread
;
686 if (likely(!test_bit(IRQTF_DIED
, &new->thread_flags
)))
694 * setup_irq - setup an interrupt
695 * @irq: Interrupt line to setup
696 * @act: irqaction for the interrupt
698 * Used to statically setup interrupts in the early boot process.
700 int setup_irq(unsigned int irq
, struct irqaction
*act
)
702 struct irq_desc
*desc
= irq_to_desc(irq
);
704 return __setup_irq(irq
, desc
, act
);
706 EXPORT_SYMBOL_GPL(setup_irq
);
709 * Internal function to unregister an irqaction - used to free
710 * regular and special interrupts that are part of the architecture.
712 static struct irqaction
*__free_irq(unsigned int irq
, void *dev_id
)
714 struct irq_desc
*desc
= irq_to_desc(irq
);
715 struct irqaction
*action
, **action_ptr
;
716 struct task_struct
*irqthread
;
719 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq
);
724 spin_lock_irqsave(&desc
->lock
, flags
);
727 * There can be multiple actions per IRQ descriptor, find the right
728 * one based on the dev_id:
730 action_ptr
= &desc
->action
;
732 action
= *action_ptr
;
735 WARN(1, "Trying to free already-free IRQ %d\n", irq
);
736 spin_unlock_irqrestore(&desc
->lock
, flags
);
741 if (action
->dev_id
== dev_id
)
743 action_ptr
= &action
->next
;
746 /* Found it - now remove it from the list of entries: */
747 *action_ptr
= action
->next
;
749 /* Currently used only by UML, might disappear one day: */
750 #ifdef CONFIG_IRQ_RELEASE_METHOD
751 if (desc
->chip
->release
)
752 desc
->chip
->release(irq
, dev_id
);
755 /* If this was the last handler, shut down the IRQ line: */
757 desc
->status
|= IRQ_DISABLED
;
758 if (desc
->chip
->shutdown
)
759 desc
->chip
->shutdown(irq
);
761 desc
->chip
->disable(irq
);
764 irqthread
= action
->thread
;
765 action
->thread
= NULL
;
767 spin_unlock_irqrestore(&desc
->lock
, flags
);
769 unregister_handler_proc(irq
, action
);
771 /* Make sure it's not being used on another CPU: */
772 synchronize_irq(irq
);
775 if (!test_bit(IRQTF_DIED
, &action
->thread_flags
))
776 kthread_stop(irqthread
);
777 put_task_struct(irqthread
);
780 #ifdef CONFIG_DEBUG_SHIRQ
782 * It's a shared IRQ -- the driver ought to be prepared for an IRQ
783 * event to happen even now it's being freed, so let's make sure that
784 * is so by doing an extra call to the handler ....
786 * ( We do this after actually deregistering it, to make sure that a
787 * 'real' IRQ doesn't run in * parallel with our fake. )
789 if (action
->flags
& IRQF_SHARED
) {
790 local_irq_save(flags
);
791 action
->handler(irq
, dev_id
);
792 local_irq_restore(flags
);
799 * remove_irq - free an interrupt
800 * @irq: Interrupt line to free
801 * @act: irqaction for the interrupt
803 * Used to remove interrupts statically setup by the early boot process.
805 void remove_irq(unsigned int irq
, struct irqaction
*act
)
807 __free_irq(irq
, act
->dev_id
);
809 EXPORT_SYMBOL_GPL(remove_irq
);
812 * free_irq - free an interrupt allocated with request_irq
813 * @irq: Interrupt line to free
814 * @dev_id: Device identity to free
816 * Remove an interrupt handler. The handler is removed and if the
817 * interrupt line is no longer in use by any driver it is disabled.
818 * On a shared IRQ the caller must ensure the interrupt is disabled
819 * on the card it drives before calling this function. The function
820 * does not return until any executing interrupts for this IRQ
823 * This function must not be called from interrupt context.
825 void free_irq(unsigned int irq
, void *dev_id
)
827 kfree(__free_irq(irq
, dev_id
));
829 EXPORT_SYMBOL(free_irq
);
832 * request_threaded_irq - allocate an interrupt line
833 * @irq: Interrupt line to allocate
834 * @handler: Function to be called when the IRQ occurs.
835 * Primary handler for threaded interrupts
836 * @thread_fn: Function called from the irq handler thread
837 * If NULL, no irq thread is created
838 * @irqflags: Interrupt type flags
839 * @devname: An ascii name for the claiming device
840 * @dev_id: A cookie passed back to the handler function
842 * This call allocates interrupt resources and enables the
843 * interrupt line and IRQ handling. From the point this
844 * call is made your handler function may be invoked. Since
845 * your handler function must clear any interrupt the board
846 * raises, you must take care both to initialise your hardware
847 * and to set up the interrupt handler in the right order.
849 * If you want to set up a threaded irq handler for your device
850 * then you need to supply @handler and @thread_fn. @handler ist
851 * still called in hard interrupt context and has to check
852 * whether the interrupt originates from the device. If yes it
853 * needs to disable the interrupt on the device and return
854 * IRQ_THREAD_WAKE which will wake up the handler thread and run
855 * @thread_fn. This split handler design is necessary to support
858 * Dev_id must be globally unique. Normally the address of the
859 * device data structure is used as the cookie. Since the handler
860 * receives this value it makes sense to use it.
862 * If your interrupt is shared you must pass a non NULL dev_id
863 * as this is required when freeing the interrupt.
867 * IRQF_SHARED Interrupt is shared
868 * IRQF_DISABLED Disable local interrupts while processing
869 * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
870 * IRQF_TRIGGER_* Specify active edge(s) or level
873 int request_threaded_irq(unsigned int irq
, irq_handler_t handler
,
874 irq_handler_t thread_fn
, unsigned long irqflags
,
875 const char *devname
, void *dev_id
)
877 struct irqaction
*action
;
878 struct irq_desc
*desc
;
882 * handle_IRQ_event() always ignores IRQF_DISABLED except for
883 * the _first_ irqaction (sigh). That can cause oopsing, but
884 * the behavior is classified as "will not fix" so we need to
885 * start nudging drivers away from using that idiom.
887 if ((irqflags
& (IRQF_SHARED
|IRQF_DISABLED
)) ==
888 (IRQF_SHARED
|IRQF_DISABLED
)) {
890 "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n",
894 #ifdef CONFIG_LOCKDEP
896 * Lockdep wants atomic interrupt handlers:
898 irqflags
|= IRQF_DISABLED
;
901 * Sanity-check: shared interrupts must pass in a real dev-ID,
902 * otherwise we'll have trouble later trying to figure out
903 * which interrupt is which (messes up the interrupt freeing
906 if ((irqflags
& IRQF_SHARED
) && !dev_id
)
909 desc
= irq_to_desc(irq
);
913 if (desc
->status
& IRQ_NOREQUEST
)
918 action
= kzalloc(sizeof(struct irqaction
), GFP_KERNEL
);
922 action
->handler
= handler
;
923 action
->thread_fn
= thread_fn
;
924 action
->flags
= irqflags
;
925 action
->name
= devname
;
926 action
->dev_id
= dev_id
;
928 retval
= __setup_irq(irq
, desc
, action
);
932 #ifdef CONFIG_DEBUG_SHIRQ
933 if (irqflags
& IRQF_SHARED
) {
935 * It's a shared IRQ -- the driver ought to be prepared for it
936 * to happen immediately, so let's make sure....
937 * We disable the irq to make sure that a 'real' IRQ doesn't
938 * run in parallel with our fake.
943 local_irq_save(flags
);
945 handler(irq
, dev_id
);
947 local_irq_restore(flags
);
953 EXPORT_SYMBOL(request_threaded_irq
);