[PATCH] CPUFREQ: Loongson2: drop set_cpus_allowed_ptr()

[PATCH] CPUFREQ: Loongson2: drop set_cpus_allowed_ptr()

[Sebastian Andrzej Siewior]

It is pure mystery to me why we need to be on a specific CPU while
looking up a value in an array.
My best shot at this is that before commit d4019f0a92ab ("cpufreq: move
freq change notifications to cpufreq core") it was required to invoke
cpufreq_notify_transition() on a special CPU.

Since it looks like a waste, remove it.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/cpufreq/loongson2_cpufreq.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/drivers/cpufreq/loongson2_cpufreq.c b/drivers/cpufreq/loongson2_cpufreq.c
index 6bbdac1065ff..9ac27b22476c 100644
--- a/drivers/cpufreq/loongson2_cpufreq.c
+++ b/drivers/cpufreq/loongson2_cpufreq.c
@@ -51,19 +51,12 @@ static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
 static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
 				     unsigned int index)
 {
-	unsigned int cpu = policy->cpu;
-	cpumask_t cpus_allowed;
 	unsigned int freq;
 
-	cpus_allowed = current->cpus_allowed;
-	set_cpus_allowed_ptr(current, cpumask_of(cpu));
-
 	freq =
 	    ((cpu_clock_freq / 1000) *
 	     loongson2_clockmod_table[index].driver_data) / 8;
 
-	set_cpus_allowed_ptr(current, &cpus_allowed);
-
 	/* setting the cpu frequency */
 	clk_set_rate(policy->clk, freq * 1000);
 
-- 
2.11.0

Re: [PATCH] CPUFREQ: Loongson2: drop set_cpus_allowed_ptr()

[Viresh Kumar]

On 04-04-17, 17:49, Sebastian Andrzej Siewior wrote:
> It is pure mystery to me why we need to be on a specific CPU while
> looking up a value in an array.
> My best shot at this is that before commit d4019f0a92ab ("cpufreq: move
> freq change notifications to cpufreq core") it was required to invoke
> cpufreq_notify_transition() on a special CPU.
> 
> Since it looks like a waste, remove it.
> 
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: linux-pm@vger.kernel.org
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>  drivers/cpufreq/loongson2_cpufreq.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/drivers/cpufreq/loongson2_cpufreq.c b/drivers/cpufreq/loongson2_cpufreq.c
> index 6bbdac1065ff..9ac27b22476c 100644
> --- a/drivers/cpufreq/loongson2_cpufreq.c
> +++ b/drivers/cpufreq/loongson2_cpufreq.c
> @@ -51,19 +51,12 @@ static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
>  static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
>  				     unsigned int index)
>  {
> -	unsigned int cpu = policy->cpu;
> -	cpumask_t cpus_allowed;
>  	unsigned int freq;
>  
> -	cpus_allowed = current->cpus_allowed;
> -	set_cpus_allowed_ptr(current, cpumask_of(cpu));
> -
>  	freq =
>  	    ((cpu_clock_freq / 1000) *
>  	     loongson2_clockmod_table[index].driver_data) / 8;
>  
> -	set_cpus_allowed_ptr(current, &cpus_allowed);
> -
>  	/* setting the cpu frequency */
>  	clk_set_rate(policy->clk, freq * 1000);

It was Zhangjin who wrote the first version and he may be able to
answer the questions we have. Anyway, it is safe to apply this patch
right now.

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

-- 
viresh

Re: [PATCH] CPUFREQ: Loongson2: drop set_cpus_allowed_ptr()

[Ralf Baechle]

On Mon, Apr 10, 2017 at 04:01:53PM +0530, Viresh Kumar wrote:

> On 04-04-17, 17:49, Sebastian Andrzej Siewior wrote:
> > It is pure mystery to me why we need to be on a specific CPU while
> > looking up a value in an array.
> > My best shot at this is that before commit d4019f0a92ab ("cpufreq: move
> > freq change notifications to cpufreq core") it was required to invoke
> > cpufreq_notify_transition() on a special CPU.
> > 
> > Since it looks like a waste, remove it.
> > 
> > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> > Cc: Viresh Kumar <viresh.kumar@linaro.org>
> > Cc: linux-pm@vger.kernel.org
> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> > ---
> >  drivers/cpufreq/loongson2_cpufreq.c | 7 -------
> >  1 file changed, 7 deletions(-)
> > 
> > diff --git a/drivers/cpufreq/loongson2_cpufreq.c b/drivers/cpufreq/loongson2_cpufreq.c
> > index 6bbdac1065ff..9ac27b22476c 100644
> > --- a/drivers/cpufreq/loongson2_cpufreq.c
> > +++ b/drivers/cpufreq/loongson2_cpufreq.c
> > @@ -51,19 +51,12 @@ static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
> >  static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
> >  				     unsigned int index)
> >  {
> > -	unsigned int cpu = policy->cpu;
> > -	cpumask_t cpus_allowed;
> >  	unsigned int freq;
> >  
> > -	cpus_allowed = current->cpus_allowed;
> > -	set_cpus_allowed_ptr(current, cpumask_of(cpu));
> > -
> >  	freq =
> >  	    ((cpu_clock_freq / 1000) *
> >  	     loongson2_clockmod_table[index].driver_data) / 8;
> >  
> > -	set_cpus_allowed_ptr(current, &cpus_allowed);
> > -
> >  	/* setting the cpu frequency */
> >  	clk_set_rate(policy->clk, freq * 1000);
> 
> It was Zhangjin who wrote the first version and he may be able to
> answer the questions we have. Anyway, it is safe to apply this patch
> right now.
> 
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Thanks for the ack, patch applied.

I noticed some of the other cpufreq drivers seem to be using similar
constructs.

  Ralf

Re: [PATCH] CPUFREQ: Loongson2: drop set_cpus_allowed_ptr()

[Sebastian Andrzej Siewior]

On 2017-04-10 13:05:11 [+0200], Ralf Baechle wrote:
> I noticed some of the other cpufreq drivers seem to be using similar
> constructs.

Don't worry, we are working on that.

>   Ralf

Sebastian