Messages in this thread | | | Subject | Re: [PATCH 07/11] PM / devfreq: check get_dev_status before start monitor | From | Chanwoo Choi <> | Date | Wed, 10 Mar 2021 12:25:31 +0900 |
| |
On 3/10/21 11:56 AM, Dong Aisheng wrote: > On Wed, Mar 10, 2021 at 12:12 AM Chanwoo Choi <cwchoi00@gmail.com> wrote: >> >> On 21. 3. 10. 오전 12:58, Chanwoo Choi wrote: >>> On 21. 3. 9. 오후 9:58, Dong Aisheng wrote: >>>> 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@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; >> >> Again, I think that get_dev_status is not used for all governors. >> So that it cause the governor start fail. Don't check whether >> .get_dev_status is NULL or not. >> > > I'm not quite understand your point. > it is used by governor_simpleondemand.c and tegra_devfreq_governor. > get_target_freq -> devfreq_update_stats -> get_dev_status
The devfreq can add the new governor by anyone. So these functions like devfreq_monitor_* have to support the governors and also must support the governor to be added in the future.
> > Without checking, device can switch to ondemand governor if it does not support. > > Am i missed something? > > Regards > Aisheng > >>>> 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); >>>> >>> >>> Need to handle the all points of devfreq_monitor_start() usage. >>> please check the tegra30-devfreq.c for this update. >>> >>> $ grep -rn "devfreq_monitor_start" drivers/ >>> drivers/devfreq/governor_simpleondemand.c:92: >>> devfreq_monitor_start(devfreq); >>> drivers/devfreq/tegra30-devfreq.c:744: >>> devfreq_monitor_start(devfreq); >>> ...... >>> >> >> >> -- >> Best Regards, >> Samsung Electronics >> Chanwoo Choi > >
-- Best Regards, Chanwoo Choi Samsung Electronics
| |