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Subject: Re: [PATCH v6 3/3] PM / devfreq: Add required OPPs support to
 passive governor
To:     Hsin-Yi Wang <hsinyi@chromium.org>,
        Viresh Kumar <vireshk@kernel.org>, linux-pm@vger.kernel.org
Cc:     Nishanth Menon <nm@ti.com>, Stephen Boyd <sboyd@kernel.org>,
        "Rafael J . Wysocki" <rjw@rjwysocki.net>,
        linux-kernel@vger.kernel.org,
        MyungJoo Ham <myungjoo.ham@samsung.com>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        Saravana Kannan <saravanak@google.com>
From:   Chanwoo Choi <cw00.choi@samsung.com>
Organization: Samsung Electronics
Message-ID: <7562fde3-cf48-fd1b-07c5-eaf02ddc15ad@samsung.com>
Date:   Thu, 4 Feb 2021 17:51:39 +0900
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        <CGME20210204081438epcas1p3f72cee2a2d14da1742f1301053794aae@epcas1p3.samsung.com>
        <20210204081424.2219311-4-hsinyi@chromium.org>
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Hi Hsin-Yi,

I have reviewed this patch already.
This version looks good to me.
I add my acked-by again.

Acked-by: Chanwoo Choi <cw00.choi@samsugn.com>

Thanks,
Chanwoo Choi

On 2/4/21 5:14 PM, Hsin-Yi Wang wrote:
> From: Saravana Kannan <saravanak@google.com>
> 
> 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 <saravanak@google.com>
> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
> Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> ---
>  drivers/devfreq/governor_passive.c | 25 ++++++++++++++++++-------
>  1 file changed, 18 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
> index 63332e4a65ae8..8fd51cc9b991a 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, *p_opp = ERR_PTR(-ENODEV);
>  	int i, count, ret = 0;
>  
>  	/*
> @@ -29,7 +29,7 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
>  	 */
>  	if (p_data->get_target_freq) {
>  		ret = p_data->get_target_freq(devfreq, freq);
> -		goto out;
> +		return ret;
>  	}
>  
>  	/*
> @@ -56,13 +56,22 @@ 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);
> -		goto out;
> +	p_opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
> +	if (IS_ERR(p_opp)) {
> +		ret = PTR_ERR(p_opp);
> +		return ret;
>  	}
>  
> -	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 (!IS_ERR(opp)) {
> +			*freq = dev_pm_opp_get_freq(opp);
> +			dev_pm_opp_put(opp);
> +		} else
> +			ret = PTR_ERR(opp);
> +		goto out;
> +	}
>  
>  	/*
>  	 * Get the OPP table's index of decided freqeuncy by governor
> @@ -89,6 +98,8 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
>  	*freq = child_freq;
>  
>  out:
> +	dev_pm_opp_put(p_opp);
> +
>  	return ret;
>  }
>  
>