Re: [PATCH v2 4/4] PM / AVS: rockchip-cpu-avs: add driver handling Rockchip cpu avs

Stephen Boyd
2016-09-12T21:55:19Z

On 08/29, Viresh Kumar wrote:
> On 18-08-16, 16:52, Finlye Xiao wrote:
> > +static int rockchip_adjust_opp_table(struct device *cpu_dev,
> > + struct cpufreq_frequency_table *table,
> > + int volt)
> > +{
> > + struct opp_table *opp_table;
> > + struct cpufreq_frequency_table *pos;
> > + struct dev_pm_opp *opp;
> > +
> > + if (!volt)
> > + return 0;
> > +
> > + rcu_read_lock();
> > +
> > + opp_table = _find_opp_table(cpu_dev);
> > + if (IS_ERR(opp_table)) {
> > + rcu_read_unlock();
> > + return PTR_ERR(opp_table);
> > + }
> > +
> > + cpufreq_for_each_valid_entry(pos, table) {
> > + opp = dev_pm_opp_find_freq_exact(cpu_dev, pos->frequency * 1000,
> > + true);
> > + if (IS_ERR(opp))
> > + continue;
> > +
> > + opp->u_volt += volt;
> > + opp->u_volt_min += volt;
> > + opp->u_volt_max += volt;
> > + }
> > +
> > + rcu_read_unlock();
> > +
> > + return 0;
> > +}
>
> I wouldn't prefer altering the opp tables from individual drivers at all. At the
> least, it should be done via some helpers exposed by the core.
>
> But before that I would like to hear from Stephen a bit as I recall he was also
> working on something similar.
>

I had a patch to modify the voltage at runtime for the "current"
OPP. Now that we have regulator and clk control inside OPP that
became a little easier to do without having to do some notifier
from the OPP layer to the consumers. I haven't had time to revive
those patches though. Should we do that? Does this need to modify
anything besides the OPP the device is currently running at?

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