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

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Message-ID: <e9c9b150-43a6-dc6b-5d88-21608120e940@codeaurora.org>
Date:   Tue, 16 Jul 2019 23:06:22 +0530
From:   Sibi Sankar <sibis@...eaurora.org>
To:     Saravana Kannan <saravanak@...gle.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Chanwoo Choi <cw00.choi@...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, adharmap@...eaurora.org
Subject: Re: [PATCH v2 3/4] PM / devfreq: Cache OPP table reference in devfreq

Hey Saravana,

On 6/26/19 3:03 AM, 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;

please add it to the function docs as well

>   	struct notifier_block nb;
>   	struct delayed_work work;
>   
> 

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