linux-kernel - Re: [PATCH v1] cpufreq: qcom: Read voltage LUT and populate OPP

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Date:   Mon, 7 Jan 2019 16:02:14 -0800
From:   Matthias Kaehlcke <mka@...omium.org>
To:     Taniya Das <tdas@...eaurora.org>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        Stephen Boyd <sboyd@...nel.org>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        devicetree@...r.kernel.org, robh@...nel.org,
        skannan@...eaurora.org, linux-arm-msm@...r.kernel.org,
        amit.kucheria@...aro.org, evgreen@...gle.com
Subject: Re: [PATCH v1] cpufreq: qcom: Read voltage LUT and populate OPP

Hi Taniya. 

On Mon, Dec 24, 2018 at 12:29:18AM +0530, Taniya Das wrote:

> Could you help validating with the patch below?

...

> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c
> b/drivers/cpufreq/qcom-cpufreq-hw.c
> index 7559b87..23338b2 100644
> --- a/drivers/cpufreq/qcom-cpufreq-hw.c
> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c
> @@ -81,7 +81,6 @@ static int qcom_cpufreq_hw_read_lut(struct device *dev,
>         u32 volt;
>         unsigned int max_cores = cpumask_weight(policy->cpus);
>         struct cpufreq_frequency_table  *table;
> -       unsigned long cpu_r;
> 
>         table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
>         if (!table)
> @@ -110,6 +109,8 @@ static int qcom_cpufreq_hw_read_lut(struct device *dev,
>                         table[i].frequency = freq;
>                         dev_dbg(dev, "index=%d freq=%d, core_count %d\n", i,
>                                 freq, core_count);
> +                       dev_pm_opp_add(get_cpu_device(policy->cpu),
> +                                       freq * 1000, volt);
>                 }
> 
>                 /*
> @@ -126,6 +127,8 @@ static int qcom_cpufreq_hw_read_lut(struct device *dev,
>                         if (prev_cc != max_cores) {
>                                 prev->frequency = prev_freq;
>                                 prev->flags = CPUFREQ_BOOST_FREQ;
> +                               dev_pm_opp_add(get_cpu_device(policy->cpu),
> +                                               prev_freq * 1000, volt);
>                         }
> 
>                         break;
> @@ -133,12 +136,9 @@ static int qcom_cpufreq_hw_read_lut(struct device *dev,
> 
>                 prev_cc = core_count;
>                 prev_freq = freq;
> -
> -               freq *= 1000;
> -               for_each_cpu(cpu_r, policy->cpus)
> -                       dev_pm_opp_add(get_cpu_device(cpu_r), freq, volt);
>         }
> 
> +       dev_pm_opp_set_sharing_cpus(get_cpu_device(policy->cpu),
> policy->cpus);
>         table[i].frequency = CPUFREQ_TABLE_END;
>         policy->freq_table = table;
> 
> @@ -245,6 +245,7 @@ static int qcom_cpufreq_hw_cpu_exit(struct
> cpufreq_policy *policy)
>  {
>         void __iomem *base = policy->driver_data - REG_PERF_STATE;
> 
> +       dev_pm_opp_cpumask_remove_table(policy->cpus);

Evan found that this doesn't actually remove dynamically added
OPPs. You'll have to use the shiny new dev_pm_opp_remove_all_dynamic()
(https://lore.kernel.org/patchwork/patch/1028942/) instead.

Cheers

Matthias