Messages in this thread | | | Date | Fri, 23 May 2014 09:35:28 +0530 | Subject | Re: [PATCH V4 3/3] cpufreq: Tegra: implement intermediate frequency callbacks | From | Viresh Kumar <> |
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On 22 May 2014 22:09, Stephen Warren <swarren@wwwdotorg.org> wrote: > I think the call to tegra_target_intermediate() is wrong here; shouldn't > the cpufreq core guarantee that tegra_target_intermediate() has always > been called before tegra_target(), so there's no need to repeat that > call here?
That's what Doug requested in the previous version. get_intermediate() can return zero in case drivers don't want to switch to intermediate frequency for some target frequency.
Core should rather guarantee that target_index() is always called, if you want core to guarantee that target_intermediate() is also always called, then don't ever return zero from get_intermediate.
I did it that way for tegra as both target_intermediate() & target_index() would have tried to set the same frequency for this particular case, i.e. when target freq == intermediate frequency.
And both would have sent notification and the last notification wouldn't have made any sense, both old-freq & new-freq would have been intermediate freqs.
So, yes I see the feature suggested by Doug quite useful. Like in your case.
> Also, tegra_target() doesn't seem to follow the rule documented by patch > 2/3 that states ->target() should restore the orignal frequency on > error. I'm not even sure if that's possible in general.
I thought I took care of that. Can you please give some example when we aren't restoring original frequency on failure ?
About the rule, that has to be the expectation from core as there is no way out that for core to know what happened at end of target_index()..
It can call get_rate() but that would be over engineering it looks ..
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