[PATCH v2 4/7] cpufreq: report whether cpufreq supports Frequency Invariance (FI)

[Viresh Kumar]

On 22-07-20, 10:37, Ionela Voinescu wrote:
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 3497c1cd6818..1d0b046fe8e9 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -61,6 +61,9 @@ static struct cpufreq_driver *cpufreq_driver;
>  static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
>  static DEFINE_RWLOCK(cpufreq_driver_lock);
>  
> +/* Mark support for the scheduler's frequency invariance engine */
> +static DEFINE_STATIC_KEY_FALSE(cpufreq_set_freq_scale);
> +
>  /* Flag to suspend/resume CPUFreq governors */
>  static bool cpufreq_suspended;
>  
> @@ -69,6 +72,25 @@ static inline bool has_target(void)
>  	return cpufreq_driver->target_index || cpufreq_driver->target;
>  }
>  
> +static inline
> +void enable_cpufreq_freq_invariance(struct cpufreq_driver *driver)
> +{
> +	if ((driver->target || driver->target_index || driver->fast_switch) &&
> +	    !driver->setpolicy) {

Just checking for !driver->setpolicy should be enough here.

> +		static_branch_enable_cpuslocked(&cpufreq_set_freq_scale);
> +		pr_debug("%s: Driver %s can provide frequency invariance.",
> +			 __func__, driver->name);

I think a simpler print will work well too.

                pr_debug("Freq invariance enabled");

__func__ isn't really required as this is the only print with that
kind of info in cpufreq.c.

> +	} else
> +		pr_err("%s: Driver %s cannot provide frequency invariance.",
> +		__func__, driver->name);

Why not supporting freq-invariance an error ? I will just drop this
message completely.

-- 
viresh