On Wed, Jan 16, 2013 at 12:14:01PM +0000, Philip, Avinash wrote:
> On Mon, Jan 14, 2013 at 12:38:56, Thierry Reding wrote:
> > On Thu, Jan 10, 2013 at 06:33:43PM +0530, Philip Avinash wrote:
> > [...]
> > > diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
> > [...]
> > > +static int ehrpwm_pwm_suspend(struct device *dev)
> > > +{
> > > + struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
> > > +
> > > + ehrpwm_pwm_context_save(pc);
> > > + pm_runtime_put_sync(dev);
> > > + return 0;
> > > +}
> > > +
> > > +static int ehrpwm_pwm_resume(struct device *dev)
> > > +{
> > > + struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
> > > +
> > > + pm_runtime_get_sync(dev);
> > > + ehrpwm_pwm_context_restore(pc);
> > > + return 0;
> > > +}
> >
> > According to Documentation/power/runtime_pm.txt, the PM core runs the
> > pm_runtime_get_noresume() and pm_runtime_put_sync() before executing the
> > .suspend() and .resume() callbacks. Are you sure you need to call them
> > here explicitly?
>
> I understand the problem of calling pm_runtime_get_sync() from .resume().
> But this has to be called if pwm was running while going to suspend so that
> pwm can continues to run after resume.
Okay. I misread the documentation and/or your patch. The documentation
says that the core calls pm_runtime_get_noresume() before executing the
.suspend() callback so you're not in fact calling it twice. Sorry for
the confusion.
> So I will add check of test_bit(PWMF_ENABLED, &pwm->flags) before
> pm_runtime_get/put_sync calls.
Yes, that sounds reasonable.
Thierry
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