linux-kernel - Re: [PATCH v3 1/3] PM: domains: Make set_performance

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Message-ID: <20210118072855.anncyl6z3e5uznvd@vireshk-i7>
Date:   Mon, 18 Jan 2021 12:58:55 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Dmitry Osipenko <digetx@...il.com>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Peter Geis <pgwipeout@...il.com>,
        Nicolas Chauvet <kwizart@...il.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Kevin Hilman <khilman@...nel.org>,
        Peter De Schrijver <pdeschrijver@...dia.com>,
        Viresh Kumar <vireshk@...nel.org>,
        Stephen Boyd <sboyd@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Matt Merhar <mattmerhar@...tonmail.com>,
        linux-kernel@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH v3 1/3] PM: domains: Make set_performance_state()
 callback optional

On 18-01-21, 04:13, Dmitry Osipenko wrote:
> Make set_performance_state() callback optional in order to remove the
> need from power domain drivers to implement a dummy callback. If callback
> isn't implemented by a GENPD driver, then the performance state is passed
> to the parent domain.
> 
> Tested-by: Peter Geis <pgwipeout@...il.com>
> Tested-by: Nicolas Chauvet <kwizart@...il.com>
> Tested-by: Matt Merhar <mattmerhar@...tonmail.com>
> Suggested-by: Ulf Hansson <ulf.hansson@...aro.org>
> Reviewed-by: Ulf Hansson <ulf.hansson@...aro.org>
> Signed-off-by: Dmitry Osipenko <digetx@...il.com>
> ---
>  drivers/base/power/domain.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 9a14eedacb92..a3e1bfc233d4 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -339,9 +339,11 @@ static int _genpd_set_performance_state(struct generic_pm_domain *genpd,
>  			goto err;
>  	}
>  
> -	ret = genpd->set_performance_state(genpd, state);
> -	if (ret)
> -		goto err;
> +	if (genpd->set_performance_state) {
> +		ret = genpd->set_performance_state(genpd, state);
> +		if (ret)
> +			goto err;
> +	}

Earlier in this routine we also have this:

if (!parent->set_performance_state)
        continue;

Should we change that too ?

>  
>  	genpd->performance_state = state;
>  	return 0;
> @@ -399,9 +401,6 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
>  	if (!genpd)
>  		return -ENODEV;
>  
> -	if (unlikely(!genpd->set_performance_state))
> -		return -EINVAL;
> -
>  	if (WARN_ON(!dev->power.subsys_data ||
>  		     !dev->power.subsys_data->domain_data))
>  		return -EINVAL;

Reviewed-by: Viresh Kumar <viresh.kumar@...aro.org>

-- 
viresh