linux-kernel - Re: [PATCH] cpufreq: pass policy to ->get() driver callback

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Message-ID: <20150911161802.GR9650@linux>
Date:	Fri, 11 Sep 2015 21:48:02 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	linaro-kernel@...ts.linaro.org, linux-pm@...r.kernel.org,
	Kristen Carlson Accardi <kristen@...ux.intel.com>,
	open list <linux-kernel@...r.kernel.org>,
	Sudeep Holla <sudeep.holla@....com>
Subject: Re: [PATCH] cpufreq: pass policy to ->get() driver callback

On 10-09-15, 23:36, Rafael J. Wysocki wrote:
> BTW, I wonder how much of the stuff in cpufreq.h can be moved to a local header
> under drivers/cpufreq/.  It looks like the majority of it is not used by
> anybody else.

Okay, will check that out and do some cleanup.

> ---
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> Subject: cpufreq: acpi-cpufreq: Use cpufreq_cpu_get_raw() in ->get()
> 
> cpufreq_cpu_get() called by get_cur_freq_on_cpu() is overkill,
> because the ->get() callback is always invoked in a context in
> which all of the conditions checked by cpufreq_cpu_get() are
> guaranteed to be satisfied.
> 
> Use cpufreq_cpu_get_raw() instead of it and drop the
> corresponding cpufreq_cpu_put() from get_cur_freq_on_cpu().
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> ---
>  drivers/cpufreq/acpi-cpufreq.c |    3 +--
>  drivers/cpufreq/cpufreq.c      |    2 +-
>  include/linux/cpufreq.h        |    5 +++++
>  3 files changed, 7 insertions(+), 3 deletions(-)
> 
> Index: linux-pm/drivers/cpufreq/acpi-cpufreq.c
> ===================================================================
> --- linux-pm.orig/drivers/cpufreq/acpi-cpufreq.c
> +++ linux-pm/drivers/cpufreq/acpi-cpufreq.c
> @@ -375,12 +375,11 @@ static unsigned int get_cur_freq_on_cpu(
>  
>  	pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
>  
> -	policy = cpufreq_cpu_get(cpu);
> +	policy = cpufreq_cpu_get_raw(cpu);
>  	if (unlikely(!policy))
>  		return 0;
>  
>  	data = policy->driver_data;
> -	cpufreq_cpu_put(policy);
>  	if (unlikely(!data || !data->freq_table))
>  		return 0;
>  
> Index: linux-pm/drivers/cpufreq/cpufreq.c
> ===================================================================
> --- linux-pm.orig/drivers/cpufreq/cpufreq.c
> +++ linux-pm/drivers/cpufreq/cpufreq.c
> @@ -238,13 +238,13 @@ int cpufreq_generic_init(struct cpufreq_
>  }
>  EXPORT_SYMBOL_GPL(cpufreq_generic_init);
>  
> -/* Only for cpufreq core internal use */
>  struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
>  {
>  	struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
>  
>  	return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
>  }
> +EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
>  
>  unsigned int cpufreq_generic_get(unsigned int cpu)
>  {
> Index: linux-pm/include/linux/cpufreq.h
> ===================================================================
> --- linux-pm.orig/include/linux/cpufreq.h
> +++ linux-pm/include/linux/cpufreq.h
> @@ -129,9 +129,14 @@ struct cpufreq_policy {
>  #define CPUFREQ_SHARED_TYPE_ANY	 (3) /* Freq can be set from any dependent CPU*/
>  
>  #ifdef CONFIG_CPU_FREQ
> +struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
>  struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
>  void cpufreq_cpu_put(struct cpufreq_policy *policy);
>  #else
> +static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
> +{
> +	return NULL;
> +}
>  static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
>  {
>  	return NULL;

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

-- 
viresh
--
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