Re: [PATCH v3 1/3] PM: domains: Make set_performance_state() callback optional

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Dmitry Osipenko <digetx@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Peter Geis <pgwipeout@gmail.com>,
	Nicolas Chauvet <kwizart@gmail.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Kevin Hilman <khilman@kernel.org>,
	Peter De Schrijver <pdeschrijver@nvidia.com>,
	Viresh Kumar <vireshk@kernel.org>,
	Stephen Boyd <sboyd@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Matt Merhar <mattmerhar@protonmail.com>,
	linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-pm@vger.kernel.org
Subject: Re: [PATCH v3 1/3] PM: domains: Make set_performance_state() callback optional
Date: Mon, 18 Jan 2021 12:58:55 +0530	[thread overview]
Message-ID: <20210118072855.anncyl6z3e5uznvd@vireshk-i7> (raw)
In-Reply-To: <20210118011330.4145-2-digetx@gmail.com>

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@gmail.com>
> Tested-by: Nicolas Chauvet <kwizart@gmail.com>
> Tested-by: Matt Merhar <mattmerhar@protonmail.com>
> Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.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@linaro.org>

-- 
viresh