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

From: Dmitry Osipenko
Date: Mon Aug 09 2021 - 19:46:50 EST


10.08.2021 01:44, Dmitry Osipenko пишет:
> 10.08.2021 01:26, Dmitry Osipenko пишет:
>> 04.08.2021 13:58, Rajendra Nayak пишет:
>>> @@ -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.

>>> + 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.

>>> + 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?
>
>>> + 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;
}