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

[Hsin-Yi Wang]

From: Saravana Kannan <sarava...@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 <sarava...@google.com>
Reviewed-by: Chanwoo Choi <cw00.c...@samsung.com>
Acked-by: MyungJoo Ham <myungjoo....@samsung.com>
Signed-off-by: Hsin-Yi Wang <hsi...@chromium.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