0a0c5168df
Introduce helper functions allowing us to prevent device drivers from getting any interrupts (without disabling interrupts on the CPU) during suspend (or hibernation) and to make them start to receive interrupts again during the subsequent resume. These functions make it possible to keep timer interrupts enabled while the "late" suspend and "early" resume callbacks provided by device drivers are being executed. In turn, this allows device drivers' "late" suspend and "early" resume callbacks to sleep, execute ACPI callbacks etc. The functions introduced here will be used to rework the handling of interrupts during suspend (hibernation) and resume. Namely, interrupts will only be disabled on the CPU right before suspending sysdevs, while device drivers will be prevented from receiving interrupts, with the help of the new helper function, before their "late" suspend callbacks run (and analogously during resume). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Ingo Molnar <mingo@elte.hu>
79 lines
1.8 KiB
C
79 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 interrupts need to be
|
|
* disabled at the chip level and this function is provided for this purpose.
|
|
* It disables all interrupt lines that are enabled at the moment and sets the
|
|
* IRQ_SUSPENDED flag for 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);
|
|
__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(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;
|
|
}
|