linux-kernel - [PATCH v5 2/3] PM / devfreq: Cache OPP table reference in devfreq

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Date:   Wed,  3 Feb 2021 17:23:59 +0800
From:   Hsin-Yi Wang <hsinyi@...omium.org>
To:     Viresh Kumar <vireshk@...nel.org>, linux-pm@...r.kernel.org
Cc:     Nishanth Menon <nm@...com>, Stephen Boyd <sboyd@...nel.org>,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        linux-kernel@...r.kernel.org,
        "MyungJoo Ham )" <myungjoo.ham@...sung.com>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Saravana Kannan <saravanak@...gle.com>
Subject: [PATCH v5 2/3] PM / devfreq: Cache OPP table reference in devfreq

From: Saravana Kannan <saravanak@...gle.com>

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>
Reviewed-by: Chanwoo Choi <cw00.choi@...sung.com>
Acked-by: MyungJoo Ham <myungjoo.ham@...sung.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@...omium.org>
---
 drivers/devfreq/devfreq.c | 6 ++++++
 include/linux/devfreq.h   | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 6aa10de792b33..a5899c9ae16fc 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -757,6 +757,8 @@ 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);
 }
@@ -844,6 +846,10 @@ struct devfreq *devfreq_add_device(struct device *dev,
 	}
 
 	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, "%s", dev_name(dev));
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index b6d3bae1c74d8..26ea0850be9bb 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -137,6 +137,7 @@ struct devfreq_stats {
  *		using devfreq.
  * @profile:	device-specific devfreq profile
  * @governor:	method how to choose frequency based on the usage.
+ * @opp_table:	Reference to OPP table of dev.parent, if one exists.
  * @nb:		notifier block used to notify devfreq object that it should
  *		reevaluate operable frequencies. Devfreq users may use
  *		devfreq.nb to the corresponding register notifier call chain.
@@ -173,6 +174,7 @@ struct devfreq {
 	struct device dev;
 	struct devfreq_dev_profile *profile;
 	const struct devfreq_governor *governor;
+	struct opp_table *opp_table;
 	struct notifier_block nb;
 	struct delayed_work work;
 
-- 
2.30.0.365.g02bc693789-goog