Re: [PATCH] PM / OPP: Call notifier without holding opp_table->lock
From: Stephen Boyd
Date: Wed Sep 20 2017 - 15:47:28 EST
On 09/20, Viresh Kumar wrote:
> On 20-09-17, 10:00, Stephen Boyd wrote:
> > On 09/20, Viresh Kumar wrote:
> > > diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
> > > index 4360b4efcd4c..668fd940d362 100644
> > > --- a/drivers/base/power/opp/core.c
> > > +++ b/drivers/base/power/opp/core.c
> > > @@ -1627,6 +1627,9 @@ static int _opp_set_availability(struct device *dev, unsigned long freq,
> > >
> > > opp->available = availability_req;
> > >
> > > + dev_pm_opp_get(opp);
> > > + mutex_unlock(&opp_table->lock);
> > Does this prevent the OPP from changing while the lock is
> > released?
> No, its just ref counting and will only prevent it from getting freed.
> There is only one thing that can change for an OPP though after it is
> created, its availability.
> > That would be the only difference from before. It's
> > possible that nobody cares about this situation though.
> I am not sure if its worth caring for right now :)
> Also the notifier chain will not start again until the previous call
> chain is finished. So we are kind of synchronized here.
Yep. Just me worrying out loud. You can add my
Reviewed-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project