linux-kernel - Re: [RFC PATCH 1/3] opp: Reduce code duplication in _set_required

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Date:   Mon, 24 Aug 2020 13:30:16 +0200
From:   Stephan Gerhold <stephan@...hold.net>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Kevin Hilman <khilman@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Nishanth Menon <nm@...com>, Stephen Boyd <sboyd@...nel.org>,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Niklas Cassel <nks@...wful.org>
Subject: Re: [RFC PATCH 1/3] opp: Reduce code duplication in
 _set_required_opps()

On Mon, Aug 24, 2020 at 04:48:20PM +0530, Viresh Kumar wrote:
> On 30-07-20, 10:01, Stephan Gerhold wrote:
> > Move call to dev_pm_genpd_set_performance_state() to a separate
> > function so we can avoid duplicating the code for the single and
> > multiple genpd case.
> > 
> > Signed-off-by: Stephan Gerhold <stephan@...hold.net>
> > ---
> >  drivers/opp/core.c | 40 +++++++++++++++++++++-------------------
> >  1 file changed, 21 insertions(+), 19 deletions(-)
> > 
> > diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> > index 9d7fb45b1786..f7a476b55069 100644
> > --- a/drivers/opp/core.c
> > +++ b/drivers/opp/core.c
> > @@ -781,6 +781,21 @@ static int _set_opp_custom(const struct opp_table *opp_table,
> >  	return opp_table->set_opp(data);
> >  }
> >  
> > +static int _set_required_opp(struct device *dev, struct device *pd_dev,
> > +			     struct dev_pm_opp *opp, int i)
> > +{
> > +	unsigned int pstate = likely(opp) ? opp->required_opps[i]->pstate : 0;
> > +	int ret;
> > +
> > +	ret = dev_pm_genpd_set_performance_state(pd_dev, pstate);
> > +	if (ret) {
> > +		dev_err(dev, "Failed to set performance rate of %s: %d (%d)\n",
> > +			dev_name(pd_dev), pstate, ret);
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> >  /* This is only called for PM domain for now */
> >  static int _set_required_opps(struct device *dev,
> >  			      struct opp_table *opp_table,
> > @@ -788,22 +803,15 @@ static int _set_required_opps(struct device *dev,
> >  {
> >  	struct opp_table **required_opp_tables = opp_table->required_opp_tables;
> >  	struct device **genpd_virt_devs = opp_table->genpd_virt_devs;
> > -	unsigned int pstate;
> > +	struct device *pd_dev;
> >  	int i, ret = 0;
> >  
> >  	if (!required_opp_tables)
> >  		return 0;
> >  
> >  	/* Single genpd case */
> > -	if (!genpd_virt_devs) {
> > -		pstate = likely(opp) ? opp->required_opps[0]->pstate : 0;
> > -		ret = dev_pm_genpd_set_performance_state(dev, pstate);
> > -		if (ret) {
> > -			dev_err(dev, "Failed to set performance state of %s: %d (%d)\n",
> > -				dev_name(dev), pstate, ret);
> > -		}
> > -		return ret;
> > -	}
> > +	if (!genpd_virt_devs)
> > +		return _set_required_opp(dev, dev, opp, 0);
> >  
> >  	/* Multiple genpd case */
> >  
> > @@ -814,17 +822,11 @@ static int _set_required_opps(struct device *dev,
> >  	mutex_lock(&opp_table->genpd_virt_dev_lock);
> >  
> >  	for (i = 0; i < opp_table->required_opp_count; i++) {
> > -		pstate = likely(opp) ? opp->required_opps[i]->pstate : 0;
> > -
> > -		if (!genpd_virt_devs[i])
> > -			continue;
> 
> Don't we need this check anymore ?
> 

You're right. Not sure why I removed it.

I suspect I had it in _set_required_opp() at some point, but I moved
code around several times until I was happy with the result.

We should just add it back.
Should I send a v2 with it fixed or would you like to handle it?

Thanks,
Stephan

> > +		pd_dev = genpd_virt_devs[i];
> >  
> > -		ret = dev_pm_genpd_set_performance_state(genpd_virt_devs[i], pstate);
> > -		if (ret) {
> > -			dev_err(dev, "Failed to set performance rate of %s: %d (%d)\n",
> > -				dev_name(genpd_virt_devs[i]), pstate, ret);
> > +		ret = _set_required_opp(dev, pd_dev, opp, i);
> > +		if (ret)
> >  			break;
> > -		}
> >  	}
> >  	mutex_unlock(&opp_table->genpd_virt_dev_lock);
> >  
> > -- 
> > 2.27.0