From: Dong Aisheng <dongas86@gmail.com>
To: Chanwoo Choi <cwchoi00@gmail.com>
Cc: Dong Aisheng <aisheng.dong@nxp.com>,
Linux PM <linux-pm@vger.kernel.org>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
Sascha Hauer <kernel@pengutronix.de>,
Shawn Guo <shawnguo@kernel.org>,
dl-linux-imx <linux-imx@nxp.com>,
open list <linux-kernel@vger.kernel.org>,
myungjoo.ham@samsung.com, kyungmin.park@samsung.com,
Chanwoo Choi <cw00.choi@samsung.com>,
Abel Vesa <abel.vesa@nxp.com>
Subject: Re: [PATCH 08/11] PM / devfreq: check get_dev_status in devfreq_update_stats
Date: Wed, 10 Mar 2021 11:00:09 +0800 [thread overview]
Message-ID: <CAA+hA=T8qezc_oL8KmoWQXg9+3MzykFxh0kW2044hBxcVpmb+g@mail.gmail.com> (raw)
In-Reply-To: <0b6ceb75-040f-8e1c-73ea-9d60344b9918@gmail.com>
On Wed, Mar 10, 2021 at 12:20 AM Chanwoo Choi <cwchoi00@gmail.com> wrote:
>
> On 21. 3. 9. 오후 9:58, Dong Aisheng wrote:
> > Check .get_dev_status() in devfreq_update_stats in case it's abused
> > when a device does not provide it.
> >
> > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
> > ---
> > drivers/devfreq/governor.h | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
> > index 31af6d072a10..67a6dbdd5d23 100644
> > --- a/drivers/devfreq/governor.h
> > +++ b/drivers/devfreq/governor.h
> > @@ -89,6 +89,9 @@ int devfreq_update_target(struct devfreq *devfreq, unsigned long freq);
> >
> > static inline int devfreq_update_stats(struct devfreq *df)
> > {
> > + if (!df->profile->get_dev_status)
> > + return -EINVAL;
> > +
>
> I'm considering the following method instead of returning the error
> when .get_dev_status is NULL.
>
> if (!df->profile->get_dev_status) {
> df->last_status.total_time = 0;
> df->last_status.busy_time = 0;
> df->last_status.current_frequency = 0;
> return 0;
> }
I might suggest not cause it's meaningless for ondemand governor but
introducing confusing. Simply return error could make the life a bit easier.
does it make sense to you?
Regards
Aisheng
>
> > return df->profile->get_dev_status(df->dev.parent, &df->last_status);
> > }
> > #endif /* _GOVERNOR_H */
> >
>
>
> --
> Best Regards,
> Samsung Electronics
> Chanwoo Choi
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next prev parent reply other threads:[~2021-03-10 3:02 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-09 12:58 [PATCH 00/11] PM / devfreq: a few small fixes and improvements Dong Aisheng
2021-03-09 12:58 ` [PATCH 01/11] doc: ABI: devfreq: remove invalid central_polling description Dong Aisheng
2021-03-09 15:01 ` Chanwoo Choi
2021-03-09 12:58 ` [PATCH 02/11] PM / devfreq: remove the invalid description for get_target_freq Dong Aisheng
2021-03-09 15:02 ` Chanwoo Choi
2021-03-09 15:14 ` Dong Aisheng
2021-03-09 12:58 ` [PATCH 03/11] PM / devfreq: fix the wrong set_freq path for userspace governor Dong Aisheng
2021-03-09 15:13 ` Chanwoo Choi
2021-03-09 15:16 ` Dong Aisheng
2021-03-09 12:58 ` [PATCH 04/11] PM / devfreq: bail out early if no freq changes in devfreq_set_target Dong Aisheng
2021-03-09 15:47 ` Chanwoo Choi
2021-03-10 2:42 ` Dong Aisheng
2021-03-09 12:58 ` [PATCH 05/11] PM / devfreq: use more accurate returned new_freq as resume_freq Dong Aisheng
2021-03-09 15:53 ` Chanwoo Choi
2021-03-10 2:43 ` Dong Aisheng
2021-03-10 3:07 ` Chanwoo Choi
2021-03-10 3:04 ` Dong Aisheng
2021-03-09 12:58 ` [PATCH 06/11] PM / devfreq: drop the unnecessary low variable initialization Dong Aisheng
2021-03-09 12:58 ` [PATCH 07/11] PM / devfreq: check get_dev_status before start monitor Dong Aisheng
2021-03-09 15:58 ` Chanwoo Choi
2021-03-09 16:12 ` Chanwoo Choi
2021-03-10 2:56 ` Dong Aisheng
2021-03-10 3:25 ` Chanwoo Choi
2021-03-10 4:56 ` Dong Aisheng
2021-03-11 7:10 ` Chanwoo Choi
2021-03-12 10:57 ` Dong Aisheng
2021-03-12 16:09 ` Chanwoo Choi
2021-03-13 6:45 ` Dong Aisheng
2021-03-18 8:03 ` Dong Aisheng
2021-03-18 9:54 ` Chanwoo Choi
2021-03-18 9:59 ` Chanwoo Choi
2021-03-18 10:51 ` Dong Aisheng
2021-03-10 2:51 ` Dong Aisheng
2021-03-09 12:58 ` [PATCH 08/11] PM / devfreq: check get_dev_status in devfreq_update_stats Dong Aisheng
2021-03-09 16:02 ` Chanwoo Choi
2021-03-09 16:20 ` Chanwoo Choi
2021-03-10 3:00 ` Dong Aisheng [this message]
2021-03-11 7:01 ` Chanwoo Choi
2021-03-09 12:58 ` [PATCH 09/11] PM / devfreq: governor: optimize simpleondemand get_target_freq Dong Aisheng
2021-03-09 16:09 ` Chanwoo Choi
2021-03-10 3:02 ` Dong Aisheng
2021-03-09 12:58 ` [PATCH 10/11] PM / devfreq: imx8m-ddrc: remove imx8m_ddrc_get_dev_status Dong Aisheng
2021-03-09 16:22 ` Chanwoo Choi
2021-03-09 12:58 ` [PATCH 11/11] PM / devfreq: imx8m-ddrc: drop polling_ms Dong Aisheng
2021-03-09 16:23 ` Chanwoo Choi
2021-03-10 3:03 ` Dong Aisheng
2021-03-09 12:58 ` [PATCH 00/11] PM / devfreq: a few small fixes and improvements Dong Aisheng
2021-03-09 12:58 ` [PATCH 01/11] doc: ABI: devfreq: remove invalid central_polling description Dong Aisheng
2021-03-09 12:58 ` [PATCH 02/11] PM / devfreq: remove the invalid description for get_target_freq Dong Aisheng
2021-03-09 12:58 ` [PATCH 03/11] PM / devfreq: fix the wrong set_freq path for userspace governor Dong Aisheng
2021-03-09 12:58 ` [PATCH 04/11] PM / devfreq: bail out early if no freq changes in devfreq_set_target Dong Aisheng
2021-03-09 12:58 ` [PATCH 05/11] PM / devfreq: use more accurate returned new_freq as resume_freq Dong Aisheng
2021-03-09 12:58 ` [PATCH 06/11] PM / devfreq: drop the unnecessary low variable initialization Dong Aisheng
2021-03-09 12:58 ` [PATCH 07/11] PM / devfreq: check get_dev_status before start monitor Dong Aisheng
2021-03-09 12:58 ` [PATCH 08/11] PM / devfreq: check get_dev_status in devfreq_update_stats Dong Aisheng
2021-03-09 12:58 ` [PATCH 09/11] PM / devfreq: governor: optimize simpleondemand get_target_freq Dong Aisheng
2021-03-09 12:58 ` [PATCH 10/11] PM / devfreq: imx8m-ddrc: remove imx8m_ddrc_get_dev_status Dong Aisheng
2021-03-09 12:58 ` [PATCH 11/11] PM / devfreq: imx8m-ddrc: drop polling_ms Dong Aisheng
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