linux-kernel - [PATCH v4 4/5] PM / devfreq: Cache OPP table reference in devfreq

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Message-Id: <20190724014222.110767-5-saravanak@google.com>
Date:   Tue, 23 Jul 2019 18:42:20 -0700
From:   Saravana Kannan <saravanak@...gle.com>
To:     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:     Saravana Kannan <saravanak@...gle.com>,
        Sibi Sankar <sibis@...eaurora.org>, kernel-team@...roid.com,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v4 4/5] PM / devfreq: Cache OPP table reference in devfreq

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>
---
 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 784c08e4f931..7984b01d585d 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -594,6 +594,8 @@ 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);
 }
@@ -674,6 +676,10 @@ 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 2bae9ed3c783..1c05129f76c0 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -116,6 +116,7 @@ struct devfreq_dev_profile {
  * @profile:	device-specific devfreq profile
  * @governor:	method how to choose frequency based on the usage.
  * @governor_name:	devfreq governor name for use with this devfreq
+ * @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.
@@ -153,6 +154,7 @@ 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;
 
-- 
2.22.0.709.g102302147b-goog