Re: [PATCH 2/4] iio: light: stk3310: Implement vdd supply and power it off during suspend

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Aren Moynihan <aren@peacevolution.org>
Cc: "Jonathan Cameron" <jic23@kernel.org>,
	"Lars-Peter Clausen" <lars@metafoo.de>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Chen-Yu Tsai" <wens@csie.org>,
	"Jernej Skrabec" <jernej.skrabec@gmail.com>,
	"Samuel Holland" <samuel@sholland.org>,
	"Liam Girdwood" <lgirdwood@gmail.com>,
	"Mark Brown" <broonie@kernel.org>, "Ondrej Jirman" <megi@xff.cz>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	linux-iio@vger.kernel.org, phone-devel@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-sunxi@lists.linux.dev,
	"Willow Barraco" <contact@willowbarraco.fr>
Subject: Re: [PATCH 2/4] iio: light: stk3310: Implement vdd supply and power it off during suspend
Date: Mon, 15 Apr 2024 17:04:53 +0300	[thread overview]
Message-ID: <CAHp75VdZavToGYqLYnkKYt53HXoQxXnRER5Cn5b2==gWTvkAWQ@mail.gmail.com> (raw)
In-Reply-To: <20240414175716.958831-2-aren@peacevolution.org>

On Sun, Apr 14, 2024 at 8:57 PM Aren Moynihan <aren@peacevolution.org> wrote:
>
> From: Ondrej Jirman <megi@xff.cz>
>
> VDD power input can be used to completely power off the chip during
> system suspend. Do so if available.

...

>  #include <linux/iio/events.h>
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>

> +#include <linux/regulator/consumer.h>

Move it to be ordered and add a blank line to separate iio/*.h group.

...

> +       data->vdd_reg = devm_regulator_get_optional(&client->dev, "vdd");
> +       if (IS_ERR(data->vdd_reg)) {
> +               ret = PTR_ERR(data->vdd_reg);
> +               if (ret == -ENODEV)
> +                       data->vdd_reg = NULL;

> +               else

Redundant 'else' when you follow the pattern "check for error condition first".

> +                       return dev_err_probe(&client->dev, ret,
> +                                            "get regulator vdd failed\n");
> +       }

...

> +       if (data->vdd_reg) {
> +               ret = regulator_enable(data->vdd_reg);
> +               if (ret)
> +                       return dev_err_probe(&client->dev, ret,
> +                                            "regulator vdd enable failed\n");
> +
> +               usleep_range(1000, 2000);

fsleep()

> +       }

...

>         stk3310_set_state(iio_priv(indio_dev), STK3310_STATE_STANDBY);
> +       if (data->vdd_reg)
> +               regulator_disable(data->vdd_reg);

I forgot to check the order of freeing resources, be sure you have no
devm_*() releases happening before this call.

...

> +               usleep_range(1000, 2000);

fsleep()

-- 
With Best Regards,
Andy Shevchenko