Re: [PATCH V3 2/3] thermal/drivers/cpu_cooling: Unregister with the policy

[Rafael J. Wysocki]

On Wed, Jun 26, 2019 at 8:37 AM Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
>
> On 26-06-19, 08:02, Daniel Lezcano wrote:
> > On 26/06/2019 04:58, Viresh Kumar wrote:
> > > On 25-06-19, 13:32, Daniel Lezcano wrote:
> > >> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> > >> index aee024e42618..f07454249fbc 100644
> > >> --- a/drivers/cpufreq/cpufreq.c
> > >> +++ b/drivers/cpufreq/cpufreq.c
> > >> @@ -1379,8 +1379,8 @@ static int cpufreq_online(unsigned int cpu)
> > >>            cpufreq_driver->ready(policy);
> > >>
> > >>    if (cpufreq_thermal_control_enabled(cpufreq_driver))
> > >> -          policy->cdev = of_cpufreq_cooling_register(policy);
> > >> -
> > >> +          of_cpufreq_cooling_register(policy);
> > >> +
> > >
> > > We don't need any error checking here anymore ?
> >
> > There was no error checking initially. This comment and the others below
> > are for an additional patch IMO, not a change in this one.
>
> right, but ...
>
> > >> -void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
> > >> +void cpufreq_cooling_unregister(struct cpufreq_policy *policy)
> > >>  {
> > >>    struct cpufreq_cooling_device *cpufreq_cdev;
> > >>    bool last;
> > >>
> > >> -  if (!cdev)
> > >> -          return;
>
> we used to return without any errors from here. Now we will have
> problems if regsitering fails for some reason.

Specifically, the last cpufreq_cdev in the list will be unregistered
AFAICS, and without removing it from the list for that matter, which
isn't what the caller wants.