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 <akhilpo@xxxxxxxxxxxxxx>
---
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
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