2021-02-03 09:29:30

by Hsin-Yi Wang

[permalink] [raw]
Subject: [PATCH v5 3/3] PM / devfreq: Add required OPPs support to passive governor

From: Saravana Kannan <[email protected]>

Look at the required OPPs of the "parent" device to determine the OPP that
is required from the slave device managed by the passive governor. This
allows having mappings between a parent device and a slave device even when
they don't have the same number of OPPs.

Signed-off-by: Saravana Kannan <[email protected]>
Acked-by: MyungJoo Ham <[email protected]>
Acked-by: Chanwoo Choi <[email protected]>
Signed-off-by: Hsin-Yi Wang <[email protected]>
---
drivers/devfreq/governor_passive.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
index 63332e4a65ae8..8d92b1964f9c3 100644
--- a/drivers/devfreq/governor_passive.c
+++ b/drivers/devfreq/governor_passive.c
@@ -19,7 +19,7 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
= (struct devfreq_passive_data *)devfreq->data;
struct devfreq *parent_devfreq = (struct devfreq *)p_data->parent;
unsigned long child_freq = ULONG_MAX;
- struct dev_pm_opp *opp;
+ struct dev_pm_opp *opp = NULL, *p_opp = NULL;
int i, count, ret = 0;

/*
@@ -56,13 +56,20 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
* list of parent device. Because in this case, *freq is temporary
* value which is decided by ondemand governor.
*/
- opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
- if (IS_ERR(opp)) {
- ret = PTR_ERR(opp);
+ p_opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
+ if (IS_ERR(p_opp)) {
+ ret = PTR_ERR(p_opp);
goto out;
}

- dev_pm_opp_put(opp);
+ if (devfreq->opp_table && parent_devfreq->opp_table)
+ opp = dev_pm_opp_xlate_required_opp(parent_devfreq->opp_table,
+ devfreq->opp_table, p_opp);
+ if (opp) {
+ *freq = dev_pm_opp_get_freq(opp);
+ dev_pm_opp_put(opp);
+ goto out;
+ }

/*
* Get the OPP table's index of decided freqeuncy by governor
@@ -89,6 +96,9 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
*freq = child_freq;

out:
+ if (!IS_ERR_OR_NULL(opp))
+ dev_pm_opp_put(p_opp);
+
return ret;
}

--
2.30.0.365.g02bc693789-goog


2021-02-04 03:11:10

by Viresh Kumar

[permalink] [raw]
Subject: Re: [PATCH v5 3/3] PM / devfreq: Add required OPPs support to passive governor

On 03-02-21, 17:24, Hsin-Yi Wang wrote:
> From: Saravana Kannan <[email protected]>
>
> Look at the required OPPs of the "parent" device to determine the OPP that
> is required from the slave device managed by the passive governor. This
> allows having mappings between a parent device and a slave device even when
> they don't have the same number of OPPs.
>
> Signed-off-by: Saravana Kannan <[email protected]>
> Acked-by: MyungJoo Ham <[email protected]>
> Acked-by: Chanwoo Choi <[email protected]>
> Signed-off-by: Hsin-Yi Wang <[email protected]>
> ---
> drivers/devfreq/governor_passive.c | 20 +++++++++++++++-----
> 1 file changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
> index 63332e4a65ae8..8d92b1964f9c3 100644
> --- a/drivers/devfreq/governor_passive.c
> +++ b/drivers/devfreq/governor_passive.c
> @@ -19,7 +19,7 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
> = (struct devfreq_passive_data *)devfreq->data;
> struct devfreq *parent_devfreq = (struct devfreq *)p_data->parent;
> unsigned long child_freq = ULONG_MAX;
> - struct dev_pm_opp *opp;
> + struct dev_pm_opp *opp = NULL, *p_opp = NULL;

I would initialize p_opp to ERR_PTR(-ENODEV) to avoid using
IS_ERR_OR_NULL. There is no need to initialize opp as well.

> int i, count, ret = 0;
>
> /*
> @@ -56,13 +56,20 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
> * list of parent device. Because in this case, *freq is temporary
> * value which is decided by ondemand governor.
> */
> - opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
> - if (IS_ERR(opp)) {
> - ret = PTR_ERR(opp);
> + p_opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
> + if (IS_ERR(p_opp)) {
> + ret = PTR_ERR(p_opp);
> goto out;

Perhaps just return from here, the goto is useless here.

> }
>
> - dev_pm_opp_put(opp);
> + if (devfreq->opp_table && parent_devfreq->opp_table)
> + opp = dev_pm_opp_xlate_required_opp(parent_devfreq->opp_table,
> + devfreq->opp_table, p_opp);
> + if (opp) {

This needs to be part of the above if block itself, else the opp will
always be NULL, isn't it ?

> + *freq = dev_pm_opp_get_freq(opp);
> + dev_pm_opp_put(opp);
> + goto out;
> + }
>
> /*
> * Get the OPP table's index of decided freqeuncy by governor
> @@ -89,6 +96,9 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
> *freq = child_freq;
>
> out:
> + if (!IS_ERR_OR_NULL(opp))

you should be checking for p_opp here, isn't it ? And perhaps we don't
need this check as well as p_opp can't be invalid here.

> + dev_pm_opp_put(p_opp);
> +
> return ret;
> }
>
> --
> 2.30.0.365.g02bc693789-goog

--
viresh

2021-02-04 07:11:32

by Hsin-Yi Wang

[permalink] [raw]
Subject: Re: [PATCH v5 3/3] PM / devfreq: Add required OPPs support to passive governor

On Thu, Feb 4, 2021 at 10:49 AM Viresh Kumar <[email protected]> wrote:
>
> On 03-02-21, 17:24, Hsin-Yi Wang wrote:
> > From: Saravana Kannan <[email protected]>
> >
> > Look at the required OPPs of the "parent" device to determine the OPP that
> > is required from the slave device managed by the passive governor. This
> > allows having mappings between a parent device and a slave device even when
> > they don't have the same number of OPPs.
> >
> > Signed-off-by: Saravana Kannan <[email protected]>
> > Acked-by: MyungJoo Ham <[email protected]>
> > Acked-by: Chanwoo Choi <[email protected]>
> > Signed-off-by: Hsin-Yi Wang <[email protected]>
> > ---
> > drivers/devfreq/governor_passive.c | 20 +++++++++++++++-----
> > 1 file changed, 15 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
> > index 63332e4a65ae8..8d92b1964f9c3 100644
> > --- a/drivers/devfreq/governor_passive.c
> > +++ b/drivers/devfreq/governor_passive.c
> > @@ -19,7 +19,7 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
> > = (struct devfreq_passive_data *)devfreq->data;
> > struct devfreq *parent_devfreq = (struct devfreq *)p_data->parent;
> > unsigned long child_freq = ULONG_MAX;
> > - struct dev_pm_opp *opp;
> > + struct dev_pm_opp *opp = NULL, *p_opp = NULL;
>
> I would initialize p_opp to ERR_PTR(-ENODEV) to avoid using
> IS_ERR_OR_NULL. There is no need to initialize opp as well.
>
> > int i, count, ret = 0;
> >
> > /*
> > @@ -56,13 +56,20 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
> > * list of parent device. Because in this case, *freq is temporary
> > * value which is decided by ondemand governor.
> > */
> > - opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
> > - if (IS_ERR(opp)) {
> > - ret = PTR_ERR(opp);
> > + p_opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
> > + if (IS_ERR(p_opp)) {
> > + ret = PTR_ERR(p_opp);
> > goto out;
>
> Perhaps just return from here, the goto is useless here.
>
> > }
> >
> > - dev_pm_opp_put(opp);
> > + if (devfreq->opp_table && parent_devfreq->opp_table)
> > + opp = dev_pm_opp_xlate_required_opp(parent_devfreq->opp_table,
> > + devfreq->opp_table, p_opp);
> > + if (opp) {
>
> This needs to be part of the above if block itself, else the opp will
> always be NULL, isn't it ?
>
> > + *freq = dev_pm_opp_get_freq(opp);
> > + dev_pm_opp_put(opp);
> > + goto out;
> > + }
> >
> > /*
> > * Get the OPP table's index of decided freqeuncy by governor
> > @@ -89,6 +96,9 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
> > *freq = child_freq;
> >
> > out:
> > + if (!IS_ERR_OR_NULL(opp))
>
> you should be checking for p_opp here, isn't it ? And perhaps we don't
> need this check as well as p_opp can't be invalid here.
>
> > + dev_pm_opp_put(p_opp);
> > +
> > return ret;
> > }
> >
> > --
> > 2.30.0.365.g02bc693789-goog
>
Thanks for the review. I'll fix them and send next version

> --
> viresh