On Thursday, September 04, 2014 04:07:28 PM Viresh Kumar wrote: > On 4 September 2014 15:33, Preeti U Murthy <pre...@linux.vnet.ibm.com> wrote: > > I think Rafael's point was that since no driver that had implemented the > > target_index callback was using it at the time that this patch was > > proposed, it was be best to couple the check on existence of stop_cpu > > callback with the the check on the kind of cpufreq driver. However > > powerpc is also in need of this today and we implement the target_index > > callback and find it convenient to use the stop CPU callback. > > No, this is what he said.. > > " > So to me, (1) the new ->stop() should *only* be called for ->setpolicy > drivers, > because the purpose of it should be to "allow ->setpolicy drivers to do what > the > GOV_STOP will do for regular drivers" > " > > > Rafael, in which case would it not make sense to remove the check on > > driver->setpolicy above? > > > > Besides, I don't understand very well why we had this double check in > > the first place. Only if the drivers are in need of the functionality > > like stop_cpu, would they have implemented this callback right? If we > > are to assume that the drivers which have implemented the target_index > > callback should never be needing it, they would not have implemented the > > stop CPU callback either. So what was that, which was blatantly wrong > > with just having a check on stop_cpu? I did go through the discussion > > but did not find a convincing answer to this. > > The idea was to get something similar to GOV_STOP for setpolicy drivers. > But in the end we didn't get to that. What we do in GOV_STOP is stop > changing CPUs frequency, but here in stop_cpu() we can stop changing > CPUs frequency OR take it to minimum, whatever we want.. > > As I said earlier, probably we should just do what you did in your patch + > some documentation changes.
OK, if that works for everybody. For one, I wouldn't like to end up with a callback used for different things in every drvier implementing it. -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
