RE: [PATCH] spi/atmel: add support for runtime PM

["Yang, Wenyou" <Wenyou.Yang@xxxxxxxxx>]

> -----Original Message-----
> From: Kevin Hilman [mailto:khilman@xxxxxxxxxx]
> Sent: Friday, October 17, 2014 10:22 PM
> To: Mark Brown
> Cc: Yang, Wenyou; linux-spi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Ferre,
> Nicolas; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH] spi/atmel: add support for runtime PM
> 
> Mark Brown <broonie@xxxxxxxxxx> writes:
> 
> > On Fri, Oct 17, 2014 at 06:02:35AM -0700, Kevin Hilman wrote:
> >> Wenyou Yang <wenyou.yang@xxxxxxxxx> writes:
> >
> >> > +	if (!pm_runtime_suspended(dev)) {
> >> > +		clk_disable_unprepare(as->clk);
> >> > +		pinctrl_pm_select_sleep_state(dev);
> >> > +	}
> >
> >> a.k.a. pm_runtime_put_sync() since the ->runtime_suspend() callback
> >> does the same thing.
> >
> > Will that do the right thing when runtime PM is disabled in Kconfig?
> 
> Good point.
> 
> Then the way to make this cleaner, and obvious on inspection that system
> suspend/resume are doing the same thing as runtime suspend/resume is to have -
> >suspend call the runtime_suspend function.
> 
> The runtime suspend/resume functions then should be wrapped in CONFIG_PM
> instead of CONFIG_PM_RUNTIME.
But if the runtime PM is disabled,  __pm_runtime_idle() return -ENOSYS, which invoked by pm_runtime_put_sync(), in spite of the runtime suspend/resume functions wrapper,

> 
> Kevin

Best Regards,
Wenyou Yang
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