On Fri, Feb 23, 2018 at 12:28:51PM +0100, Daniel Lezcano wrote:
> On 23/02/2018 08:34, Viresh Kumar wrote:
> > On 21-02-18, 16:29, Daniel Lezcano wrote:
> [ ... ]
>
> >> +static s64 cpuidle_cooling_runtime(struct cpuidle_cooling_device
> >> *idle_cdev)
> >> +{
> >> + s64 next_wakeup;
> >> + int state = idle_cdev->state;
> >> +
> >> + /*
> >> + * The function must never be called when there is no
> >> + * mitigation because:
> >> + * - that does not make sense
> >> + * - we end up with a division by zero
> >> + */
> >> + BUG_ON(!state);
> >
> > As there is no locking in place, we can surely hit this case. What if
> > the state changed to 0 right before this routine was called ?
> >
> > I would suggest we should just return 0 in that case and get away with
> > the BUG_ON().
Here if 'state' equals to 0 and we return 0, then the return value will
be same with when 'state' = 100; this lets the return value confused.
I think for 'state' = 0, should we return -1 so indicate the hrtimer
will not be set for this case?
Thanks,
Leo Yan
