[PATCH] PM / devfreq: comments for get_dev_status usage updated

[PATCH] PM / devfreq: comments for get_dev_status usage updated

[MyungJoo Ham]

With the introduction of devfreq_update_stats(), governors
are not recommended to use get_dev_status() directly.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
---
 include/linux/devfreq.h | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 70a1c60..68030e2 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -65,7 +65,10 @@ struct devfreq_dev_status {
  *			The "flags" parameter's possible values are
  *			explained above with "DEVFREQ_FLAG_*" macros.
  * @get_dev_status:	The device should provide the current performance
- *			status to devfreq, which is used by governors.
+ *			status to devfreq. Governors are recommended not to
+ *			use this directly. Instead, governors are recommended
+ *			to use devfreq_update_stats() along with
+ *			devfreq.last_status.
  * @get_cur_freq:	The device should provide the current frequency
  *			at which it is operating.
  * @exit:		An optional callback that is called when devfreq
@@ -208,6 +211,10 @@ extern void devm_devfreq_unregister_opp_notifier(struct device *dev,
 /**
  * devfreq_update_stats() - update the last_status pointer in struct devfreq
  * @df:		the devfreq instance whose status needs updating
+ *
+ *  Governors are recommended to use this function along with last_status,
+ * which allows other entities to reuse the last_status without affecting
+ * the values fetched later by governors.
  */
 static inline int devfreq_update_stats(struct devfreq *df)
 {
-- 
1.9.1

Re: [PATCH] PM / devfreq: comments for get_dev_status usage updated

[Javi Merino]

On Tue, Aug 18, 2015 at 05:52:46AM +0100, MyungJoo Ham wrote:
> 
> With the introduction of devfreq_update_stats(), governors
> are not recommended to use get_dev_status() directly.
> 
> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
> ---
>  include/linux/devfreq.h | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
Looks good to me.  FWIW,

Reviewed-by: Javi Merino <javi.merino@arm.com>