On Mon, Nov 23, 2015 at 6:13 PM, MyungJoo Ham <myungjoo....@samsung.com> wrote: >> On Mon, Nov 23, 2015 at 4:21 PM, MyungJoo Ham <myungjoo....@samsung.com> >> wrote: >> > [] >> >> > >> >> > The value 0 is used for min/max_freq to declare >> >> > that min/max_freq is deactivated. Therefore, it is not >> >> > required to do so; they are not intended to show the hardware >> >> > configuration as well. >> >> >> >> This case consider the devfreq device using OPP because >> >> devfreq_set_freq_table() >> >> get the number of OPP entry in OPP list before setting the >> >> min_freq/max_freq. >> >> If the devfreq device don't use the OPP entry, devfreq_set_freq_table() >> >> will return without any operation. >> >> >> >> IMHO, when devfreq device uses the OPP table including the frequency, >> >> min_freq/max_freq should show the correct value as CPUFREQ framework. >> >> >> > >> > The side effect of this patch shows up when opp_disable() and opp_enable() >> > are used. >> >> Ah. You're right. >> I was not considering the the case of using opp_disable() and opp_enable(). >> I'll consider it again including the usage case of opp_diable/opp_enable. >> > > Even without the side effect, what would be the meaning of initializing > min/max-freq to the device min/max capabilities when the users may > override it with arbitrary lower/higher values?
Yes, the user can update min_freq/max_freq because this attribute have the writable permission. The users might think that min_freq/max_freq provide the users with the minimum and maximum frequency. because CPUFREQ show the frequency on scaling_min_freq / scaling_max_freq. But, right after kernel booting, min_freq/max_freq is zero (0). I think that it cause the confusion for users. Regards, Chanwoo Choi -- 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/
