Re: [RFC][PATCH 2/2] PM: Rework handling of interrupts during suspend-resume

Ingo Molnar
2009-02-23T12:29:45Z

* Rafael J. Wysocki <rjw@sisk.pl> wrote:

> > > Index: linux-2.6/arch/x86/kernel/apm_32.c
> > > ===================================================================
> > > --- linux-2.6.orig/arch/x86/kernel/apm_32.c
> > > +++ linux-2.6/arch/x86/kernel/apm_32.c
> >
> > > +
> > > + suspend_device_irqs();
> > > device_power_down(PMSG_SUSPEND);
> > > +
> > > + local_irq_disable();
> >
> > hm, this is a very repetitive pattern, all around the various
> > suspend/resume variants. Might make sense to make:
> >
> > device_power_down(PMSG_SUSPEND);
> >
> > do the irq line disabling plus the local irq disabling
> > automatically. That also means it cannot be forgotten. The
> > symmetric action should happen for PMSG_RESUME.
> >
> > Is there ever a case where we want a different pattern?
>
> Even if there's no such case, I prefer to call
> local_irq_disable() explicitly in here, so that it's clearly
> known where it happens to anyone reading this code.

That property can be implied in the function name:

device_power_down_irq_disable(PMSG_SUSPEND);

Open-coding it, if it looks the same in all the cases just
increases the chances that someone somewhere copies them
incorrectly.

Ingo