Messages in this thread | | | Date | Thu, 24 Feb 2022 09:33:18 +0000 | Subject | Re: [PATCH v3 3/4] OPP: Add support of "opp-microwatt" for advanced EM registration | From | Lukasz Luba <> |
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On 2/24/22 09:13, Viresh Kumar wrote: > On 24-02-22, 08:11, Lukasz Luba wrote: >> diff --git a/drivers/opp/of.c b/drivers/opp/of.c >> >> +/* >> + * Callback function provided to the Energy Model framework upon registration. >> + * It provides the power used by @dev at @kHz if it is the frequency of an >> + * existing OPP, or at the frequency of the first OPP above @kHz otherwise >> + * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled >> + * frequency and @mW to the associated power. >> + * >> + * Returns 0 on success or a proper -EINVAL value in case of error. >> + */ >> +static int __maybe_unused >> +_get_opp_power(unsigned long *mW, unsigned long *kHz, struct device *dev) > > Lets call it _get_dt_opp_power() or _get_dt_power() ?
OK, I'll return to _get_dt_power()
> >> +{ >> + struct dev_pm_opp *opp; >> + unsigned long opp_freq, opp_power; >> + >> + /* Find the right frequency and related OPP */ >> + opp_freq = *kHz * 1000; >> + opp = dev_pm_opp_find_freq_ceil(dev, &opp_freq); >> + if (IS_ERR(opp)) >> + return -EINVAL; >> + >> + opp_power = dev_pm_opp_get_power(opp); > > As I said in 2/4, this should really give the total instead.
make sense
> >> + dev_pm_opp_put(opp); >> + if (!opp_power) >> + return -EINVAL; >> + >> + *kHz = opp_freq / 1000; >> + *mW = opp_power / 1000; >> + >> + return 0; >> +} >> + >> /* >> * Callback function provided to the Energy Model framework upon registration. >> * This computes the power estimated by @dev at @kHz if it is the frequency >> @@ -1488,6 +1520,24 @@ static int __maybe_unused _get_power(unsigned long *mW, unsigned long *kHz, >> return 0; >> } >> >> +static bool _of_has_opp_microwatt_property(struct device *dev) >> +{ >> + unsigned long power, freq = 0; >> + struct dev_pm_opp *opp; >> + >> + /* Check if at least one OPP has needed property */ >> + opp = dev_pm_opp_find_freq_ceil(dev, &freq); >> + if (IS_ERR(opp)) >> + return false; >> + >> + power = dev_pm_opp_get_power(opp); >> + dev_pm_opp_put(opp); >> + if (!power) > > What if this particular frequency has 0 power mentioned for some > reason :)
If that power 0 would be allowed here, then in next step when EM calls active_power() we check !power and report dev_err(). IPA design would also not accept the power=0
> > Instead of this heavy stuff, just pick the first OPP from the opp > table and see its power-value.
It is the first opp: freq=0. You mean by parsing the the DT node instead, like I had in v2 version?
> >> + return false; >> + >> + return true; >> +} >> + >> /** >> * dev_pm_opp_of_register_em() - Attempt to register an Energy Model >> * @dev : Device for which an Energy Model has to be registered >> @@ -1517,6 +1567,14 @@ int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus) >> goto failed; >> } >> >> + /* First, try to find more precised Energy Model in DT */ >> + if (_of_has_opp_microwatt_property(dev)) { >> + struct em_data_callback em_dt_cb = EM_DATA_CB(_get_opp_power); >> + >> + return em_dev_register_perf_domain(dev, nr_opp, &em_dt_cb, >> + cpus, true); >> + } >> + > > We have another em_dev_register_perf_domain() down the line, lets keep > only one such call and get it a callback that should be set in an > if/else loop.
OK
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