On Wed, Jun 26, 2019 at 12:19 PM Daniel Lezcano
<daniel.lezcano@xxxxxxxxxx> wrote:
>
> On 26/06/2019 11:06, Rafael J. Wysocki wrote:
> > 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.
>
> Indeed,
>
> What about the resulting code above:
>
> void __cpufreq_cooling_unregister(struct cpufreq_cooling_device
> *cpufreq_cdev, int last)
> {
> /* Unregister the notifier for the last cpufreq cooling device */
> if (last)
> cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
> CPUFREQ_POLICY_NOTIFIER);
>
Doesn't the notifier need to be unregistered under cooling_list_lock ?
> thermal_cooling_device_unregister(cpufreq_cdev->cdev);
> ida_simple_remove(&cpufreq_ida, cpufreq_cdev->id);
> kfree(cpufreq_cdev->idle_time);
> kfree(cpufreq_cdev);
> }
>
> /**
>
> * cpufreq_cooling_unregister - function to remove cpufreq cooling
> device.
> * @cdev: thermal cooling device pointer.
>
> *
>
> * This interface function unregisters the "thermal-cpufreq-%x" cooling
> device.
> */
> void cpufreq_cooling_unregister(struct cpufreq_policy *policy)
> {
> struct cpufreq_cooling_device *cpufreq_cdev;
> bool last;
>
> mutex_lock(&cooling_list_lock);
> list_for_each_entry(cpufreq_cdev, &cpufreq_cdev_list, node) {
> if (cpufreq_cdev->policy == policy) {
> list_del(&cpufreq_cdev->node);
> last = list_empty(&cpufreq_cdev_list);
> break;
> }
> }
> mutex_unlock(&cooling_list_lock);
>
> if (cpufreq_cdev->policy == policy)
> __cpufreq_cooling_unregister(cpufreq_cdev, last);
> }
> EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);
>
>
>
>
> --
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