On Monday, July 04, 2011, MyungJoo Ham wrote: > Hello, > > 2011/7/3 Rafael J. Wysocki <rjw@xxxxxxx>: > > Hi, > > > > On Friday, May 27, 2011, MyungJoo Ham wrote: > >> Three CPUFREQ-like governors are provided as examples. > >> > >> powersave: use the lowest frequency possible. The user (device) should > >> set the polling_ms as 0 because polling is useless for this governor. > >> > >> performance: use the highest freqeuncy possible. The user (device) > >> should set the polling_ms as 0 because polling is useless for this > >> governor. > >> > >> simple_ondemand: simplified version of CPUFREQ's ONDEMAND governor. > >> > >> When a user updates OPP entries (enable/disable/add), OPP framework > >> automatically notifies DEVFREQ to update operating frequency > >> accordingly. Thus, DEVFREQ users (device drivers) do not need to update > >> DEVFREQ manually with OPP entry updates or set polling_ms for powersave > >> , performance, or any other "static" governors. > >> > >> Signed-off-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx> > >> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > [] > >> + > >> + /* Set the desired frequency based on the load */ > >> + a = (unsigned long long) stat.busy_time * stat.current_frequency; > > > > What's the purpose of the conversion? > > Assuming that the work speed of a device is proportional to its > frequency, it measures the amount of work done. > It's time * work/time. For example, during the last 10 second, if the > busy_time was 5 sec and frequency was 10MHz, > it's "50M", which is same as 20MHz and 2.5 sec. I understand that, but my question was why you're doing a forced conversion to (unsigned long long). Thanks, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
