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.d...@nxp.com> --- 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