Re: [PATCH v2 3/6] iio: chemical: atlas-sensor: Balance runtime pm + pm_runtime_resume_and_get()

[Matt Ranostay <matt.ranostay@konsulko.com>]

On Sun, May 16, 2021 at 9:22 AM Jonathan Cameron <jic23@kernel.org> wrote:
>
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>
> The pm_runtime_put_noidle() call in remove isn't balanced with any get, so
> drop it.  Note this isn't a bug as the runtime pm core will not allow the
> reference count to go negative, making this a noop. However, it is
> confusing to the reader so let's drop it.
>
> pm_runtime_resume_and_get() replacement found using the coccicheck script
> under review at:
> https://lore.kernel.org/lkml/20210427141946.2478411-1-Julia.Lawall@inria.fr/
>
> As pm_runtime_resume_and_get() returns <= 0 take advantage of that to
> change the error checking to if (ret) which is more in keeping with the
> rest of this driver.
>
> This is a prequel to taking a closer look at the runtime pm in IIO drivers
> in general.
>

Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>

> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Cc: Matt Ranostay <matt.ranostay@konsulko.com>
> ---
>  drivers/iio/chemical/atlas-sensor.c | 13 ++++---------
>  1 file changed, 4 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/iio/chemical/atlas-sensor.c b/drivers/iio/chemical/atlas-sensor.c
> index 0fdb3b29c5eb..9cb99585b6ff 100644
> --- a/drivers/iio/chemical/atlas-sensor.c
> +++ b/drivers/iio/chemical/atlas-sensor.c
> @@ -410,11 +410,9 @@ static int atlas_buffer_postenable(struct iio_dev *indio_dev)
>         struct atlas_data *data = iio_priv(indio_dev);
>         int ret;
>
> -       ret = pm_runtime_get_sync(&data->client->dev);
> -       if (ret < 0) {
> -               pm_runtime_put_noidle(&data->client->dev);
> +       ret = pm_runtime_resume_and_get(&data->client->dev);
> +       if (ret)
>                 return ret;
> -       }
>
>         return atlas_set_interrupt(data, true);
>  }
> @@ -487,11 +485,9 @@ static int atlas_read_measurement(struct atlas_data *data, int reg, __be32 *val)
>         int suspended = pm_runtime_suspended(dev);
>         int ret;
>
> -       ret = pm_runtime_get_sync(dev);
> -       if (ret < 0) {
> -               pm_runtime_put_noidle(dev);
> +       ret = pm_runtime_resume_and_get(dev);
> +       if (ret)
>                 return ret;
> -       }
>
>         if (suspended)
>                 msleep(data->chip->delay);
> @@ -741,7 +737,6 @@ static int atlas_remove(struct i2c_client *client)
>
>         pm_runtime_disable(&client->dev);
>         pm_runtime_set_suspended(&client->dev);
> -       pm_runtime_put_noidle(&client->dev);
>
>         return atlas_set_powermode(data, 0);
>  }
> --
> 2.31.1
>