linux-kernel - Re: [PATCH] cpufreq: scpi: invoke frequency-invariance setter function

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Date:   Wed, 21 Feb 2018 09:05:51 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Dietmar Eggemann <dietmar.eggemann@....com>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Sudeep Holla <sudeep.holla@....com>
Subject: Re: [PATCH] cpufreq: scpi: invoke frequency-invariance setter
 function

On 20-02-18, 11:10, Dietmar Eggemann wrote:
> Commit 343a8d17fa8d ("cpufreq: scpi: remove arm_big_little dependency")
> changed the cpufreq driver on juno from arm_big_little to scpi.
> 
> The scpi set_target function does not call the frequency-invariance
> setter function arch_set_freq_scale() like the arm_big_little set_target
> function does. As a result the task scheduler load and utilization
> signals are not frequency-invariant on this platform anymore.
> 
> Fix this by adding a call to arch_set_freq_scale() into
> scpi_cpufreq_set_target().
> 
> Fixes: 343a8d17fa8d ("cpufreq: scpi: remove arm_big_little dependency")
> Cc: Rafael J. Wysocki <rjw@...ysocki.net>
> Cc: Viresh Kumar <viresh.kumar@...aro.org>
> Cc: Sudeep Holla <sudeep.holla@....com>
> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@....com>
> Acked-by: Sudeep Holla <sudeep.holla@....com>
> ---
>  drivers/cpufreq/scpi-cpufreq.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
> index c32a833e1b00..3101d4e9c2de 100644
> --- a/drivers/cpufreq/scpi-cpufreq.c
> +++ b/drivers/cpufreq/scpi-cpufreq.c
> @@ -51,13 +51,19 @@ static unsigned int scpi_cpufreq_get_rate(unsigned int cpu)
>  static int
>  scpi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
>  {
> +	unsigned long freq = policy->freq_table[index].frequency;
>  	struct scpi_data *priv = policy->driver_data;
> -	u64 rate = policy->freq_table[index].frequency * 1000;
> +	u64 rate = freq * 1000;
>  	int ret;
>  
>  	ret = clk_set_rate(priv->clk, rate);
> -	if (!ret && (clk_get_rate(priv->clk) != rate))
> -		ret = -EIO;
> +	if (!ret) {
> +		if (clk_get_rate(priv->clk) != rate)
> +			ret = -EIO;
> +
> +		arch_set_freq_scale(policy->related_cpus, freq,
> +				    policy->cpuinfo.max_freq);
> +	}
>  
>  	return ret;
>  }

Acked-by: Viresh Kumar <viresh.kumar@...aro.org>

-- 
viresh