Re: [PATCH 4/4] mfd: global Suspend and resume support of ehci andohci

From: Felipe Balbi
Date: Sun Jun 05 2011 - 14:51:33 EST


Hi,

On Sun, Jun 05, 2011 at 07:19:38PM +0200, Rafael J. Wysocki wrote:
> > On Wed, Jun 01, 2011 at 03:54:38PM +0200, Rafael J. Wysocki wrote:
> > > > +static const struct dev_pm_ops usbhsomap_dev_pm_ops = {
> > > > + .suspend = usbhs_suspend,
> > > > + .resume = usbhs_resume,
> > > > +};
> > >
> > > Please add .freeze()/.thaw() and .poweroff()/.restore() callbacks too.
> > > They may point to the same routines, but must be present.
> > >
> > > You can actually use the SIMPLE_DEV_PM_OPS() convenience macro for this
> > > purpose.
> >
> > good point. BTW, do we need this #ifdef CONFIG_PM stuff which has been
> > popping on most drivers recently ? To me it looks like driver.pm field
> > is always available even if PM is disabled, so what's the point ? Saving
> > a few bytes ?
>
> Basically, yes (you may want to avoid defining the object this points to if
> CONFIG_PM is unset).

wouldn't it look nicer to have a specific section for dev_pm_ops which
gets automatically freed if CONFIG_PM isn't set ? I mean, there are a
few drivers which don't have the ifdeferry around dev_pm_ops anyway.

So, something like:

#define __pm_ops __section(.pm.ops)

static const struct dev_pm_ops my_driver_pm_ops __pm_ops = {
.suspend = my_driver_suspend,
.resume = my_driver_resume,
[ blablabla ]
};

to simplify things, you could:

#define DEFINE_DEV_PM_OPS(_ops) \
const struct dev_pm_ops _ops __pm_ops

that would mean changes to all linker scripts, though and a utility call
that only does anything ifndef CONFIG_PM to free the .pm.ops section.

--
balbi

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