Re: [PATCH] cpufreq: exynos5440: Fix to skip when new frequency same as current

From: Rafael J. Wysocki
Date: Wed Aug 07 2013 - 19:14:59 EST

On Wednesday, August 07, 2013 05:03:59 PM Viresh Kumar wrote:
> On 7 August 2013 17:00, Sudeep KarkadaNagesha
> <Sudeep.KarkadaNagesha@xxxxxxx> wrote:
> > Any particular reason we need this check in all drivers after your
> > commit: 5a1c0228 "cpufreq: Avoid calling cpufreq driver's target()
> > routine if target_freq == policy->cur"
> >
> > I think it can removed from all drivers, am I missing something ?
> Yeah.. Just a bit though :)
> So, cpufreq core checks this when we call target for any frequency.
> Now, cpufreq driver actually does a cpufreq_frequency_table_target()
> and so the frequency may vary than what is requested, in case
> requested frequency isn't picked from the table.
> In such cases we check it again to be sure that we aren't at this
> frequency already..
> Earlier I thought of calling cpufreq_frequency_table_target() in the
> core before calling target but dropped the idea as I wasn't sure of
> the side effects.
> @Rafael: Do you see why we shouldn't/can't call
> cpufreq_frequency_table_target() from the core itself and so drivers
> never need to do it?

It looks like it would require us to redefine .target() to take next_state
instead of target_freq (at least in the acpi-cpufreq case), wouldn't it?


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at