[PATCH 04/12] PM / devfreq: Cache OPP table reference in devfreq

Andrew-sh.Cheng
2020-05-20T03:54:11Z

From: Saravana Kannan <saravanak@google.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@google.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.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 6fecd11dafdd..1103a3ae5586 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -719,6 +719,8 @@ 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);
}
@@ -797,6 +799,10 @@ 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 57e871a559a9..a4b19d593151 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -131,6 +131,7 @@ struct devfreq_stats {
* @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.
@@ -168,6 +169,7 @@ 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;

--
2.12.5