[PATCH 07/11] PM / devfreq: check get_dev_status before start monitor

From: Dong Aisheng
Date: Tue Mar 09 2021 - 08:14:37 EST


The devfreq monitor depends on the device to provide load information
by .get_dev_status() to calculate the next target freq.

And this will cause changing governor to simple ondemand fail
if device can't support.

Signed-off-by: Dong Aisheng <aisheng.dong@xxxxxxx>
---
drivers/devfreq/devfreq.c | 10 +++++++---
drivers/devfreq/governor.h | 2 +-
drivers/devfreq/governor_simpleondemand.c | 3 +--
3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 7231fe6862a2..d1787b6c7d7c 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -482,10 +482,13 @@ static void devfreq_monitor(struct work_struct *work)
* to be called from governor in response to DEVFREQ_GOV_START
* event when device is added to devfreq framework.
*/
-void devfreq_monitor_start(struct devfreq *devfreq)
+int devfreq_monitor_start(struct devfreq *devfreq)
{
if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
- return;
+ return 0;
+
+ if (!devfreq->profile->get_dev_status)
+ return -EINVAL;

switch (devfreq->profile->timer) {
case DEVFREQ_TIMER_DEFERRABLE:
@@ -495,12 +498,13 @@ void devfreq_monitor_start(struct devfreq *devfreq)
INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor);
break;
default:
- return;
+ return -EINVAL;
}

if (devfreq->profile->polling_ms)
queue_delayed_work(devfreq_wq, &devfreq->work,
msecs_to_jiffies(devfreq->profile->polling_ms));
+ return 0;
}
EXPORT_SYMBOL(devfreq_monitor_start);

diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
index 5cee3f64fe2b..31af6d072a10 100644
--- a/drivers/devfreq/governor.h
+++ b/drivers/devfreq/governor.h
@@ -75,7 +75,7 @@ struct devfreq_governor {
unsigned int event, void *data);
};

-void devfreq_monitor_start(struct devfreq *devfreq);
+int devfreq_monitor_start(struct devfreq *devfreq);
void devfreq_monitor_stop(struct devfreq *devfreq);
void devfreq_monitor_suspend(struct devfreq *devfreq);
void devfreq_monitor_resume(struct devfreq *devfreq);
diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
index d57b82a2b570..ea287b57cbf3 100644
--- a/drivers/devfreq/governor_simpleondemand.c
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -89,8 +89,7 @@ static int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
{
switch (event) {
case DEVFREQ_GOV_START:
- devfreq_monitor_start(devfreq);
- break;
+ return devfreq_monitor_start(devfreq);

case DEVFREQ_GOV_STOP:
devfreq_monitor_stop(devfreq);
--
2.25.1