linux-kernel - Re: [PATCH v5 4/8] soc: qcom: rpmpd: Add support for get/set performance state

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Date:   Tue, 04 Dec 2018 15:14:29 -0800
From:   Stephen Boyd <sboyd@...nel.org>
To:     Rajendra Nayak <rnayak@...eaurora.org>, andy.gross@...aro.org,
        collinsd@...eaurora.org, mka@...omium.org, robh@...nel.org,
        ulf.hansson@...aro.org, viresh.kumar@...aro.org
Cc:     devicetree@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Rajendra Nayak <rnayak@...eaurora.org>
Subject: Re: [PATCH v5 4/8] soc: qcom: rpmpd: Add support for get/set performance
 state

Quoting Rajendra Nayak (2018-12-03 21:21:15)
> @@ -221,6 +224,47 @@ static int rpmpd_power_off(struct generic_pm_domain *domain)
>         return ret;
>  }
>  
> +static int rpmpd_set_performance(struct generic_pm_domain *domain,
> +                                unsigned int state)
> +{
> +       int ret = 0;
> +       struct rpmpd *pd = domain_to_rpmpd(domain);
> +
> +       mutex_lock(&rpmpd_lock);
> +
> +       if (state > MAX_RPMPD_STATE)
> +               goto out;

Does this need to be under the mutex lock? Doesn't look like it.

> +
> +       pd->corner = state;
> +
> +       if (!pd->enabled && (pd->key != KEY_FLOOR_CORNER))

Please drop useless parenthesis.

> +               goto out;
> +
> +       ret = rpmpd_aggregate_corner(pd);
> +
> +out:
> +       mutex_unlock(&rpmpd_lock);
> +
> +       return ret;
> +}
> +
> +static unsigned int rpmpd_get_performance(struct generic_pm_domain *genpd,
> +                                         struct dev_pm_opp *opp)
> +{
> +       struct device_node *np;
> +       unsigned int corner = 0;
> +
> +       np = dev_pm_opp_get_of_node(opp);
> +       if (of_property_read_u32(np, "qcom,level", &corner)) {
> +               pr_err("%s: missing 'qcom,level' property\n", __func__);

We leak np reference here, assuming dev_pm_opp_get_of_node() returns an
of_node_get() pointer to the caller.

> +               return 0;
> +       }
> +
> +       of_node_put(np);

This same code exists twice. Perhaps a helper needs to exist for
qcom_rpm_get_performance() to pull the number out of the DT.

> +
> +       return corner;
> +}