android_kernel_cmhtcleo/kernel/irq/pm.c
Abhijeet Dharmapurikar 43b7c2a243 genirq: pm: Fix the enable ordering in resume
In suspend interrupts are disabled from 0 to NR_IRQ, in resume interrupts
should be enabled in reverse order.

Enabling parent or summary interrupts before enabling child interrupts
causes the handler of the child interrupt to run even before it is
enabled. Usually the genirq handler does the correct thing of masking
the interrupt and additionally marking the interrupt IRQ_PENDING if its
an edge triggered interrupt. However the nested handler
(handle_nested_irq()) simply ignores the interrupt causing a loss of it.

Not calling the action of an interrupt, especially if it marked wakeup,
causes the system to incorrectly go back to suspend immediately.

Change-Id: Ica30c10a975a4a7b41b97b4f21250dac80335b2b
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
2011-03-23 01:41:36 +08:00

81 lines
1.8 KiB
C

/*
* linux/kernel/irq/pm.c
*
* Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
* This file contains power management functions related to interrupts.
*/
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include "internals.h"
/**
* suspend_device_irqs - disable all currently enabled interrupt lines
*
* During system-wide suspend or hibernation device drivers need to be prevented
* from receiving interrupts and this function is provided for this purpose.
* It marks all interrupt lines in use, except for the timer ones, as disabled
* and sets the IRQ_SUSPENDED flag for each of them.
*/
void suspend_device_irqs(void)
{
struct irq_desc *desc;
int irq;
for_each_irq_desc(irq, desc) {
unsigned long flags;
spin_lock_irqsave(&desc->lock, flags);
if (desc->wake_depth == 0)
__disable_irq(desc, irq, true);
spin_unlock_irqrestore(&desc->lock, flags);
}
for_each_irq_desc(irq, desc)
if (desc->status & IRQ_SUSPENDED)
synchronize_irq(irq);
}
EXPORT_SYMBOL_GPL(suspend_device_irqs);
/**
* resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs()
*
* Enable all interrupt lines previously disabled by suspend_device_irqs() that
* have the IRQ_SUSPENDED flag set.
*/
void resume_device_irqs(void)
{
struct irq_desc *desc;
int irq;
for_each_irq_desc_reverse(irq, desc) {
unsigned long flags;
if (!(desc->status & IRQ_SUSPENDED))
continue;
spin_lock_irqsave(&desc->lock, flags);
__enable_irq(desc, irq, true);
spin_unlock_irqrestore(&desc->lock, flags);
}
}
EXPORT_SYMBOL_GPL(resume_device_irqs);
/**
* check_wakeup_irqs - check if any wake-up interrupts are pending
*/
int check_wakeup_irqs(void)
{
struct irq_desc *desc;
int irq;
for_each_irq_desc(irq, desc)
if ((desc->status & IRQ_WAKEUP) && (desc->status & IRQ_PENDING))
return -EBUSY;
return 0;
}