Re: [PATCH] cpufreq: scmi: Fix frequency invariance in slow path

Viresh Kumar
2019-01-09T10:45:20Z

On 09-01-19, 10:42, Quentin Perret wrote:
> The scmi-cpufreq driver calls the arch_set_freq_scale() callback on
> frequency changes to provide scale-invariant load-tracking signals to
> the scheduler. However, in the slow path, it does so while specifying
> the current and max frequencies in different units, hence resulting in a
> broken freq_scale factor.
>
> Fix this by passing all frequencies in KHz, as stored in the CPUFreq
> frequency table.
>
> Fixes: 99d6bdf33877 ("cpufreq: add support for CPU DVFS based on SCMI
> message protocol")
> Signed-off-by: Quentin Perret <quentin.perret@arm.com>
> ---
> drivers/cpufreq/scmi-cpufreq.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c
> index 50b1551ba894..3f0693439486 100644
> --- a/drivers/cpufreq/scmi-cpufreq.c
> +++ b/drivers/cpufreq/scmi-cpufreq.c
> @@ -52,9 +52,9 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
> int ret;
> struct scmi_data *priv = policy->driver_data;
> struct scmi_perf_ops *perf_ops = handle->perf_ops;
> - u64 freq = policy->freq_table[index].frequency * 1000;
> + u64 freq = policy->freq_table[index].frequency;
>
> - ret = perf_ops->freq_set(handle, priv->domain_id, freq, false);
> + ret = perf_ops->freq_set(handle, priv->domain_id, freq * 1000, false);
> if (!ret)
> arch_set_freq_scale(policy->related_cpus, freq,
> policy->cpuinfo.max_freq);

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

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viresh