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
