alistair23-linux/kernel/irq/resend.c
Linus Torvalds 88ffc35059 Revert "genirq: temporary fix for level-triggered IRQ resend"
This reverts commit 0fc4969b86.  It was
always meant to be temporary, but it's generating more useless noise
than anything else, and we probably should never have done it in the
generic kernel (only had the people involved test it on their own).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-09 08:10:16 -07:00

78 lines
1.8 KiB
C

/*
* linux/kernel/irq/resend.c
*
* Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
* Copyright (C) 2005-2006, Thomas Gleixner
*
* This file contains the IRQ-resend code
*
* If the interrupt is waiting to be processed, we try to re-run it.
* We can't directly run it from here since the caller might be in an
* interrupt-protected region. Not all irq controller chips can
* retrigger interrupts at the hardware level, so in those cases
* we allow the resending of IRQs via a tasklet.
*/
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
#include "internals.h"
#ifdef CONFIG_HARDIRQS_SW_RESEND
/* Bitmap to handle software resend of interrupts: */
static DECLARE_BITMAP(irqs_resend, NR_IRQS);
/*
* Run software resends of IRQ's
*/
static void resend_irqs(unsigned long arg)
{
struct irq_desc *desc;
int irq;
while (!bitmap_empty(irqs_resend, NR_IRQS)) {
irq = find_first_bit(irqs_resend, NR_IRQS);
clear_bit(irq, irqs_resend);
desc = irq_desc + irq;
local_irq_disable();
desc->handle_irq(irq, desc);
local_irq_enable();
}
}
/* Tasklet to handle resend: */
static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0);
#endif
/*
* IRQ resend
*
* Is called with interrupts disabled and desc->lock held.
*/
void check_irq_resend(struct irq_desc *desc, unsigned int irq)
{
unsigned int status = desc->status;
/*
* Make sure the interrupt is enabled, before resending it:
*/
desc->chip->enable(irq);
if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY;
if (!desc->chip || !desc->chip->retrigger ||
!desc->chip->retrigger(irq)) {
#ifdef CONFIG_HARDIRQS_SW_RESEND
/* Set it pending and activate the softirq: */
set_bit(irq, irqs_resend);
tasklet_schedule(&resend_tasklet);
#endif
}
}
}