Re: [PATCH v2 3/3] cpufreq: CPPC: Register EM based on efficiency class information

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Pierre Gondois <pierre.gondois@arm.com>
Cc: linux-kernel@vger.kernel.org, Ionela.Voinescu@arm.com,
	Lukasz.Luba@arm.com, Morten.Rasmussen@arm.com,
	Dietmar.Eggemann@arm.com, maz@kernel.org,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Ard Biesheuvel <ardb@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Fuad Tabba <tabba@google.com>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Rob Herring <robh@kernel.org>, Lee Jones <lee.jones@linaro.org>,
	linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org
Subject: Re: [PATCH v2 3/3] cpufreq: CPPC: Register EM based on efficiency class information
Date: Mon, 11 Apr 2022 08:42:31 +0530	[thread overview]
Message-ID: <20220411031231.noq5yprp5oui3lsx@vireshk-i7> (raw)
In-Reply-To: <20220407081620.1662192-4-pierre.gondois@arm.com>

On 07-04-22, 10:16, Pierre Gondois wrote:
> +static void cppc_cpufreq_register_em(struct cpufreq_policy *policy)
> +{
> +	struct cppc_cpudata *cpu_data;
> +	struct em_data_callback em_cb =
> +		EM_ADV_DATA_CB(cppc_get_cpu_power, cppc_get_cpu_cost);
> +
> +	if (!efficiency_class_populated)

Instead of a new variable for this, what about setting
cppc_cpufreq_driver.register_em = cppc_cpufreq_register_em, only if
you were able to populate the efficiency class in the first place ?

> +		return;
> +
> +	cpu_data = cppc_cpufreq_search_cpu_data(policy->cpu);
> +	em_dev_register_perf_domain(get_cpu_device(policy->cpu),
> +			get_perf_level_count(policy), &em_cb,
> +			cpu_data->shared_cpu_map, 0);
> +}
> +
>  #else
>  
>  static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
> @@ -471,6 +609,9 @@ static int populate_efficiency_class(void)
>  {
>  	return 0;
>  }
> +static void cppc_cpufreq_register_em(struct cpufreq_policy *policy)
> +{
> +}
>  #endif
>  
>  
> @@ -742,6 +883,7 @@ static struct cpufreq_driver cppc_cpufreq_driver = {
>  	.init = cppc_cpufreq_cpu_init,
>  	.exit = cppc_cpufreq_cpu_exit,
>  	.set_boost = cppc_cpufreq_set_boost,
> +	.register_em = cppc_cpufreq_register_em,
>  	.attr = cppc_cpufreq_attr,
>  	.name = "cppc_cpufreq",
>  };
> -- 
> 2.25.1

-- 
viresh