Re: [update, rev. 6] Re: [PATCH 1/10] PM: Rework handling of interrupts during suspend-resume (rev. 5)

From: Rafael J. Wysocki
Date: Fri Mar 13 2009 - 17:57:20 EST


On Friday 13 March 2009, Thomas Gleixner wrote:
> On Thu, 12 Mar 2009, Rafael J. Wysocki wrote:
> > +/**
> > + * 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);
>
> Can we move the locking into __disable_irq ?

Well, yes, but (see below)

> > + }
> > +
> > + 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);
>
> Ditto

No, because of __setup_irq().

Thanks,
Rafael
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