Re: [PATCH v6 1/2] PM / Domains: Add support for 'required-opps' to set default perf state

10.08.2021 02:46, Dmitry Osipenko пишет:

10.08.2021 01:44, Dmitry Osipenko пишет:

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10.08.2021 01:26, Dmitry Osipenko пишет:

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04.08.2021 13:58, Rajendra Nayak пишет:

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@@ -2637,6 +2643,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 {
 	struct of_phandle_args pd_args;
 	struct generic_pm_domain *pd;
+	struct device_node *np;
+	int pstate;
 	int ret;
 
 	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",

@@ -2675,10 +2683,26 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 		genpd_unlock(pd);
 	}
 
-	if (ret)
+	if (ret) {
 		genpd_remove_device(pd, dev);
+		return -EPROBE_DEFER;
+	}
+
+	/* Set the default performance state */
+	np = dev->of_node;
+	if (of_parse_phandle(np, "required-opps", index)) {

The OF node returned by of_parse_phandle() must be put.

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+		pstate = of_get_required_opp_performance_state(np, index);

If you have more than one power domain, then this will override the
pstate which was set for a previous domain. This code doesn't feel solid
to me, at least a clarifying comment is needed about how it's supposed
to work.

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+		if (pstate < 0) {
+			ret = pstate;
+			dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",
+				pd->name, ret);
+		} else {
+			dev_pm_genpd_set_performance_state(dev, pstate);

Where is error handling?

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+			dev_gpd_data(dev)->default_pstate = pstate;
+		}
+	}

Why performance state is set after genpd_power_on()?

Should set_performance_state() be invoked when power_on=false?

I assume it should be:

if (power_on) {
	dev_pm_genpd_set_performance_state(dev, pstate);
	dev_gpd_data(dev)->default_pstate = pstate;
} else {
	dev_gpd_data(dev)->rpm_pstate = pstate;
}

Although, thinking a bit more about this, it should be better to skip
setting perf state in a case of power_on=false and let drivers to handle
it, IMO. Too much trouble with it for the core.