linux-kernel - Re: [PATCH v2 3/4] PM / devfreq: Cache OPP table reference in devfreq

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Date:   Wed, 26 Jun 2019 10:57:14 +0900
From:   Chanwoo Choi <cw00.choi@...sung.com>
To:     Saravana Kannan <saravanak@...gle.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...nel.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:     kernel-team@...roid.com, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        "cpgs (cpgs@...sung.com)" <cpgs@...sung.com>
Subject: Re: [PATCH v2 3/4] PM / devfreq: Cache OPP table reference in
 devfreq

Hi Saravana,

On 19. 6. 26. 오전 6:33, Saravana Kannan wrote:
> The OPP table can be used often in devfreq. Trying to get it each time can
> be expensive, so cache it in the devfreq struct.
> 
> Signed-off-by: Saravana Kannan <saravanak@...gle.com>
> ---
>  drivers/devfreq/devfreq.c | 6 ++++++
>  include/linux/devfreq.h   | 1 +
>  2 files changed, 7 insertions(+)
> 
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 6b6991f0e873..ac62b78dc035 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -597,6 +597,8 @@ static void devfreq_dev_release(struct device *dev)
>  	if (devfreq->profile->exit)
>  		devfreq->profile->exit(devfreq->dev.parent);
>  
> +	if (devfreq->opp_table)
> +		dev_pm_opp_put_opp_table(devfreq->opp_table);
>  	mutex_destroy(&devfreq->lock);
>  	kfree(devfreq);
>  }
> @@ -677,6 +679,10 @@ struct devfreq *devfreq_add_device(struct device *dev,
>  	devfreq->max_freq = devfreq->scaling_max_freq;
>  
>  	devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
> +	devfreq->opp_table = dev_pm_opp_get_opp_table(dev);
> +	if (IS_ERR(devfreq->opp_table))
> +		devfreq->opp_table = NULL;
> +
>  	atomic_set(&devfreq->suspend_count, 0);
>  
>  	dev_set_name(&devfreq->dev, "devfreq%d",
> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
> index fbffa74bfc1b..0d877c9513d7 100644
> --- a/include/linux/devfreq.h
> +++ b/include/linux/devfreq.h
> @@ -156,6 +156,7 @@ struct devfreq {
>  	struct devfreq_dev_profile *profile;
>  	const struct devfreq_governor *governor;
>  	char governor_name[DEVFREQ_NAME_LEN];
> +	struct opp_table *opp_table;
>  	struct notifier_block nb;
>  	struct delayed_work work;
>  
> 

Looks good to me.
Reviewed-by: Chanwoo Choi <cw00.choi@...sung.com>

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics