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

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Message-ID: <d9317471-fb81-482a-22c1-4a7b466a1df4@codeaurora.org>
Date:   Wed, 5 Dec 2018 12:33:14 +0530
From:   Rajendra Nayak <rnayak@...eaurora.org>
To:     Stephen Boyd <sboyd@...nel.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
Subject: Re: [PATCH v5 4/8] soc: qcom: rpmpd: Add support for get/set
 performance state



On 12/5/2018 4:44 AM, Stephen Boyd wrote:
> 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.

Nope, will move it out.

> 
>> +
>> +       pd->corner = state;
>> +
>> +       if (!pd->enabled && (pd->key != KEY_FLOOR_CORNER))
> 
> Please drop useless parenthesis.

sure

> 
>> +               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.

good catch, will fix.

> 
>> +               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.

Sure I can make both drivers use a common helper instead of duplicating it.

> 
>> +
>> +       return corner;
>> +}