Re: [PATCH 1/10] PM: Rework handling of interrupts during suspend-resume (rev. 5)

Thomas Gleixner
2009-03-11T10:33:01Z

Rafael,

On Wed, 11 Mar 2009, Rafael J. Wysocki wrote:

> Index: linux-2.6/kernel/irq/pm.c
> ===================================================================
> --- /dev/null
> +++ linux-2.6/kernel/irq/pm.c
> @@ -0,0 +1,89 @@
> +/*
> + * 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;
> + bool sync = false;
> +
> + spin_lock_irqsave(&desc->lock, flags);
> +
> + if (desc->action && !(desc->action->flags & IRQF_TIMER)) {
> + if (!desc->depth++) {
> + desc->status |= IRQ_DISABLED;
> + desc->chip->disable(irq);
> + sync = true;
> + }
> + desc->status |= IRQ_SUSPENDED;

This flag needs to be checked in __enable_irq().

> + }
> +
> + spin_unlock_irqrestore(&desc->lock, flags);
> +
> + if (sync)
> + synchronize_irq(irq);
> + }
> +}
> +EXPORT_SYMBOL_GPL(suspend_device_irqs);

I'm not too enthusiastic about this open coded implementation of
disable_irq() with slightly different semantics.

Can we please move the fiddling with desc->* into
kernel/irq/manage.c and share the code there ?

> +/**
> + * 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);
> + desc->status &= ~IRQ_SUSPENDED;
> + __enable_irq(desc, irq);
> + spin_unlock_irqrestore(&desc->lock, flags);
> + }
> +}
> +EXPORT_SYMBOL_GPL(resume_device_irqs);

Ditto.

Thanks,

tglx