linux-kernel - Re: [PATCH V3 5/5] cpufreq: Add QoS requests for userspace constraints

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Date:   Mon, 17 Jun 2019 08:37:37 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Matthias Kaehlcke <mka@...omium.org>
Cc:     Rafael Wysocki <rjw@...ysocki.net>, linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Qais.Yousef@....com, juri.lelli@...il.com,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH V3 5/5] cpufreq: Add QoS requests for userspace
 constraints

On 14-06-19, 10:14, Matthias Kaehlcke wrote:
> Hi Viresh,
> 
> On Mon, Jun 10, 2019 at 04:21:36PM +0530, Viresh Kumar wrote:
> > This implements QoS requests to manage userspace configuration of min
> > and max frequency.
> > 
> > Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
> > ---
> >  drivers/cpufreq/cpufreq.c | 92 +++++++++++++++++++--------------------
> >  include/linux/cpufreq.h   |  8 +---
> >  2 files changed, 47 insertions(+), 53 deletions(-)
> > 
> > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> > index 547d221b2ff2..ff754981fcb4 100644
> > --- a/drivers/cpufreq/cpufreq.c
> > +++ b/drivers/cpufreq/cpufreq.c
> > @@ -720,23 +720,15 @@ static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
> >  static ssize_t store_##file_name					\
> >  (struct cpufreq_policy *policy, const char *buf, size_t count)		\
> >  {									\
> > -	int ret, temp;							\
> > -	struct cpufreq_policy new_policy;				\
> > +	unsigned long val;						\
> > +	int ret;							\
> >  									\
> > -	memcpy(&new_policy, policy, sizeof(*policy));			\
> > -	new_policy.min = policy->user_policy.min;			\
> > -	new_policy.max = policy->user_policy.max;			\
> > -									\
> > -	ret = sscanf(buf, "%u", &new_policy.object);			\
> > +	ret = sscanf(buf, "%lu", &val);					\
> >  	if (ret != 1)							\
> >  		return -EINVAL;						\
> >  									\
> > -	temp = new_policy.object;					\
> > -	ret = cpufreq_set_policy(policy, &new_policy);		\
> > -	if (!ret)							\
> > -		policy->user_policy.object = temp;			\
> > -									\
> > -	return ret ? ret : count;					\
> > +	ret = dev_pm_qos_update_request(policy->object##_freq_req, val);\
> > +	return ret && ret != 1 ? ret : count;				\
> 
> nit: I wonder if
> 
>   return (ret >= 0) ? count : ret;
> 
> would be clearer.

Done. Thanks.

> Other than that:
> 
> Reviewed-by: Matthias Kaehlcke <mka@...omium.org>

-- 
viresh