Re: [PATCH 4/4] PM / devfreq: passive: Reduce duplicate code when passive_devfreq case

[Chanwoo Choi]

Hi Matthias,

On 21. 6. 23. 오전 3:35, Matthias Kaehlcke wrote:
> On Thu, Jun 17, 2021 at 03:05:46PM +0900, Chanwoo Choi wrote:
> > In order to keep the consistent coding style between passive_devfreq
> > and passive_cpufreq, use common code for handling required opp property.
> > Also remove the unneed conditional statement and unify the comment
> > of both passive_devfreq and passive_cpufreq when getting the target frequency.
> >
> > Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> > ---
> >   drivers/devfreq/governor_passive.c | 80 ++++++------------------------
> >   1 file changed, 15 insertions(+), 65 deletions(-)
> >
> > diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
> > index 07e864509b7e..7102cb7eb30d 100644
> > --- a/drivers/devfreq/governor_passive.c
> > +++ b/drivers/devfreq/governor_passive.c
> > @@ -91,66 +91,17 @@ static int get_target_freq_with_devfreq(struct devfreq *devfreq,
> >   	struct devfreq_passive_data *p_data
> >   			= (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, *p_opp;
> > -	int i, count;
> > -
> > -	/*
> > -	 * If the devfreq device with passive governor has the specific method
> > -	 * to determine the next frequency, should use the get_target_freq()
> > -	 * of struct devfreq_passive_data.
> > -	 */
> > -	if (p_data->get_target_freq)
> > -		return p_data->get_target_freq(devfreq, freq);
> > -
> > -	/*
> > -	 * If the parent and passive devfreq device uses the OPP table,
> > -	 * get the next frequency by using the OPP table.
> > -	 */
> > -
> > -	/*
> > -	 * - parent devfreq device uses the governors except for passive.
> > -	 * - passive devfreq device uses the passive governor.
> > -	 *
> > -	 * Each devfreq has the OPP table. After deciding the new frequency
> > -	 * from the governor of parent devfreq device, the passive governor
> > -	 * need to get the index of new frequency on OPP table of parent
> > -	 * device. And then the index is used for getting the suitable
> > -	 * new frequency for passive devfreq device.
> > -	 */
> > -	if (!devfreq->profile || !devfreq->profile->freq_table
> > -		|| devfreq->profile->max_state <= 0)
> > -		return -EINVAL;
> > -
> > -	/*
> > -	 * The passive governor have to get the correct frequency from OPP
> > -	 * list of parent device. Because in this case, *freq is temporary
> > -	 * value which is decided by ondemand governor.
> > -	 */
> > -	if (devfreq->opp_table && parent_devfreq->opp_table) {
> > -		p_opp = devfreq_recommended_opp(parent_devfreq->dev.parent,
> > -						freq, 0);
> > -		if (IS_ERR(p_opp))
> > -			return PTR_ERR(p_opp);
> > -
> > -		opp = dev_pm_opp_xlate_required_opp(parent_devfreq->opp_table,
> > -						    devfreq->opp_table, p_opp);
> > -		dev_pm_opp_put(p_opp);
> > -
> > -		if (IS_ERR(opp))
> > -			goto no_required_opp;
> > -
> > -		*freq = dev_pm_opp_get_freq(opp);
> > -		dev_pm_opp_put(opp);
> > -
> > -		return 0;
> > -	}
> > +	unsigned long target_freq;
> > +	int i;
> > +
> > +	/* Get target freq via required opps */
> > +	target_freq = get_taget_freq_by_required_opp(parent_devfreq->dev.parent,
> > +						parent_devfreq->opp_table,
> > +						devfreq->opp_table, *freq);
>
> s/get_taget_freq_by_required_opp/get_target_freq_by_required_opp/
>
> Also need to be fixed in "[3/4] PM / devfreq: Add cpu based scaling
> support to passive governor".

Thanks for catch. I'll fix it.

> > +	if (target_freq)
> > +		goto out;
> >   
> > -no_required_opp:
> > -	/*
> > -	 * Get the OPP table's index of decided frequency by governor
> > -	 * of parent device.
> > -	 */
> > +	/* Use Interpolation if required opps is not available */
>
> s/Interpolation/interpolation/

I'll fix it.

> >   	for (i = 0; i < parent_devfreq->profile->max_state; i++)
> >   		if (parent_devfreq->profile->freq_table[i] == *freq)
> >   			break;
> > @@ -158,16 +109,15 @@ static int get_target_freq_with_devfreq(struct devfreq *devfreq,
> >   	if (i == parent_devfreq->profile->max_state)
> >   		return -EINVAL;
> >   
> > -	/* Get the suitable frequency by using index of parent device. */
> >   	if (i < devfreq->profile->max_state) {
> > -		child_freq = devfreq->profile->freq_table[i];
> > +		target_freq = devfreq->profile->freq_table[i];
> >   	} else {
> > -		count = devfreq->profile->max_state;
> > -		child_freq = devfreq->profile->freq_table[count - 1];
> > +		i = devfreq->profile->max_state;
> > +		target_freq = devfreq->profile->freq_table[i - 1];
> >   	}
> >   
> > -	/* Return the suitable frequency for passive device. */
> > -	*freq = child_freq;
> > +out:
> > +	*freq = target_freq;
>
> You might want to split the child_freq => target_freq and commentary change into
> a separate patch, since it is not directly related with the switch to
> get_target_freq_by_required_opp().

OK. I will not change about child_freq -> target_freq.


--
Best Regards,
Samsung Electronics
Chanwoo Choi