Re: [PATCH V2 1/2] cpufreq: ondemand: allow custom powersave_bias_target function to be registered

Borislav Petkov
2013-04-02T12:43:36Z

On Thu, Mar 28, 2013 at 01:24:16PM -0500, Jacob Shin wrote:
> This allows for another [arch specific] driver to hook into existing
> powersave bias function of the ondemand governor. i.e. This allows AMD
> specific powersave bias function (in a separate AMD specific driver)
> to aid ondemand governor's frequency transition deicisions.
>
> Signed-off-by: Jacob Shin <jacob.shin@amd.com>
> ---
> drivers/cpufreq/cpufreq_governor.h | 3 +++
> drivers/cpufreq/cpufreq_ondemand.c | 22 +++++++++++++++++++---
> 2 files changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq_governor.h b/drivers/cpufreq/cpufreq_governor.h
> index c83cabf..4b6808f 100644
> --- a/drivers/cpufreq/cpufreq_governor.h
> +++ b/drivers/cpufreq/cpufreq_governor.h
> @@ -262,4 +262,7 @@ bool need_load_eval(struct cpu_dbs_common_info *cdbs,
> unsigned int sampling_rate);
> int cpufreq_governor_dbs(struct cpufreq_policy *policy,
> struct common_dbs_data *cdata, unsigned int event);
> +void od_register_powersave_bias_function(unsigned int (*f)
> + (struct cpufreq_policy *, unsigned int, unsigned int));
> +void od_unregister_powersave_bias_function(void);

We generally call those a "callback" or a "handler". I.e.,
od_register_powersave_bias_handler or something.

> #endif /* _CPUFREQ_GOVERNER_H */
> diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
> index 15e80ee..36f0798 100644
> --- a/drivers/cpufreq/cpufreq_ondemand.c
> +++ b/drivers/cpufreq/cpufreq_ondemand.c
> @@ -40,6 +40,8 @@
>
> static DEFINE_PER_CPU(struct od_cpu_dbs_info_s, od_cpu_dbs_info);
>
> +static struct od_ops od_ops;
> +
> #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
> static struct cpufreq_governor cpufreq_gov_ondemand;
> #endif
> @@ -145,7 +147,8 @@ static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq)
> struct od_dbs_tuners *od_tuners = dbs_data->tuners;
>
> if (od_tuners->powersave_bias)
> - freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H);
> + freq = od_ops.powersave_bias_target(p, freq,
> + CPUFREQ_RELATION_H);
> else if (p->cur == p->max)
> return;
>
> @@ -206,8 +209,8 @@ static void od_check_cpu(int cpu, unsigned int load_freq)
> __cpufreq_driver_target(policy, freq_next,
> CPUFREQ_RELATION_L);
> } else {
> - int freq = powersave_bias_target(policy, freq_next,
> - CPUFREQ_RELATION_L);
> + int freq = od_ops.powersave_bias_target(policy,
> + freq_next, CPUFREQ_RELATION_L);
> __cpufreq_driver_target(policy, freq,
> CPUFREQ_RELATION_L);
> }
> @@ -565,6 +568,19 @@ static struct common_dbs_data od_dbs_cdata = {
> .exit = od_exit,
> };
>
> +void od_register_powersave_bias_function(unsigned int (*f)
> + (struct cpufreq_policy *, unsigned int, unsigned int))
> +{
> + od_ops.powersave_bias_target = f;
> +}
> +EXPORT_SYMBOL_GPL(od_register_powersave_bias_function);
> +
> +void od_unregister_powersave_bias_function(void)
> +{
> + od_ops.powersave_bias_target = powersave_bias_target;

This is very confusing: we have ->powersave_bias_target and the default
powersave_bias_target in the ondemand governor. Can we call the default
one generic_powersave_bias_target or default_* or whatever.

Thanks.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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