On 04/29/2014 01:34 PM, Viresh Kumar wrote: > On 29 April 2014 13:05, Srivatsa S. Bhat > <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> wrote: >> On 04/29/2014 12:19 PM, Viresh Kumar wrote: >>> + WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) >>> && (current == policy->transition_task)); >>> >>> which you already mentioned. >> >> Yeah, I think we should just go with this. I thought we needed lots of >> if-conditions to do exclude these drivers (which would have made it ugly), >> but as you pointed above, just this one would suffice. > > Okay, I think we can do one more modification here: > >>> + WARN_ON(unlikely(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) >>> && (current == policy->transition_task))); > WARN_ON and friends already wrap their arguments within unlikely(). So we don't need to add it explicitly. > >> Besides, the cpufreq core doesn't automatically invoke _begin() and >> _end() for ASYNC_NOTIFICATION drivers. So that means the probability >> that such drivers will hit this problem is extremely low, since the >> driver alone is responsible for invoking _begin/_end and hence there >> shouldn't be much of a conflict. So I think we should really just >> skip ASYNC_NOTIFICATION drivers in this debug infrastructure. > > The only way it can happen (I don't hope somebody would be so > stupid to call begin twice from target() :)), is via transition notifiers, > which in some case starting a new transition.. Hmm.. Regards, Srivatsa S. Bhat -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
