[RFC] PM / devfreq: Add support for alerts
From: Akhil P Oommen <hidden>
Date: 2018-05-31 05:37:16
Also in:
linux-arm-msm, lkml
Subsystem:
device frequency (devfreq), the rest · Maintainers:
MyungJoo Ham, Kyungmin Park, Chanwoo Choi, Linus Torvalds
Currently, DEVFREQ reevaluates the device state periodically and/or based on the OPP list changes. Private API has to be exposed to allow the device driver to alert/notify the governor to reevaluate when a new set of data is available. This makes the governor more coupled to a particular device driver. We can improve here by exposing a DEVFREQ API to allow the device drivers to send generic alerts to the governor. Signed-off-by: Akhil P Oommen <redacted> --- drivers/devfreq/devfreq.c | 21 +++++++++++++++++++++ drivers/devfreq/governor.h | 1 + include/linux/devfreq.h | 5 +++++ 3 files changed, 27 insertions(+)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index fe2af6a..24a8046 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c@@ -1532,3 +1532,24 @@ void devm_devfreq_unregister_notifier(struct device *dev, devm_devfreq_dev_match, devfreq)); } EXPORT_SYMBOL(devm_devfreq_unregister_notifier); + +/** + * devfreq_alert_governor() - Alert governor about an event + * @devfreq: The devfreq object. + * @type: Optional alert type. + * + * This function lets the device alert the governor about an event. + * A governor may not implement or choose to completely ignore this alert. + */ +void devfreq_alert_governor(struct devfreq *devfreq, unsigned int type) +{ + /* Don't let someone change the governor until we are done here. */ + mutex_lock(&devfreq_list_lock); + + if (devfreq) + devfreq->governor->event_handler(devfreq, + DEVFREQ_GOV_ALERT, &type); + + mutex_unlock(&devfreq_list_lock); +} +EXPORT_SYMBOL(devfreq_alert_governor);
diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
index cfc50a6..e5da3442 100644
--- a/drivers/devfreq/governor.h
+++ b/drivers/devfreq/governor.h@@ -24,6 +24,7 @@ #define DEVFREQ_GOV_INTERVAL 0x3 #define DEVFREQ_GOV_SUSPEND 0x4 #define DEVFREQ_GOV_RESUME 0x5 +#define DEVFREQ_GOV_ALERT 0x6 /** * struct devfreq_governor - Devfreq policy governor
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 3aae5b3..740c228 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h@@ -193,6 +193,7 @@ extern struct devfreq *devm_devfreq_add_device(struct device *dev, void *data); extern void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq); +extern void devfreq_alert_governor(struct devfreq *devfreq, unsigned int type); /* Supposed to be called by PM callbacks */ extern int devfreq_suspend_device(struct devfreq *devfreq);
@@ -306,6 +307,10 @@ static inline void devm_devfreq_remove_device(struct device *dev, { } +static void devfreq_alert_governor(struct devfreq *devfreq, unsigned int type) +{ +} + static inline int devfreq_suspend_device(struct devfreq *devfreq) { return 0;
--
1.9.1