Re: [PATCH] iio: max5481: use devres for iio device registration

From: Jonathan Cameron
Date: Sun Aug 18 2019 - 13:19:04 EST


On Wed, 14 Aug 2019 11:21:44 +0200
Martin Kaiser <martin@xxxxxxxxx> wrote:

> Replace iio_device_register with the devres variant and drop the
> explicit function call to unregister the iio device.
>
> Signed-off-by: Martin Kaiser <martin@xxxxxxxxx>
This changes the order of removal compared to probe as now we don't remove
the userspace interface before storing to non volatile memory.

Admittedly it's a pretty unlikely race to hit but I don't want to set
a precedent of judging just how unlikely a race is.

I'm also not keen to use dev_add_action_or_reset for this one as the
action in remove is not balanced to one in probe - I want to see it
clearly laid out in code, as it currently is.

So a no on this sort of change in this particular driver.

Thanks,

Jonathan

> ---
> drivers/iio/potentiometer/max5481.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/iio/potentiometer/max5481.c b/drivers/iio/potentiometer/max5481.c
> index 732375b6d131..40b7212e68dc 100644
> --- a/drivers/iio/potentiometer/max5481.c
> +++ b/drivers/iio/potentiometer/max5481.c
> @@ -162,7 +162,7 @@ static int max5481_probe(struct spi_device *spi)
> if (ret < 0)
> return ret;
>
> - return iio_device_register(indio_dev);
> + return devm_iio_device_register(&spi->dev, indio_dev);
> }
>
> static int max5481_remove(struct spi_device *spi)
> @@ -170,8 +170,6 @@ static int max5481_remove(struct spi_device *spi)
> struct iio_dev *indio_dev = dev_get_drvdata(&spi->dev);
> struct max5481_data *data = iio_priv(indio_dev);
>
> - iio_device_unregister(indio_dev);
> -
> /* save wiper reg to NV reg */
> return max5481_write_cmd(data, MAX5481_COPY_AB_TO_NV, 0);
> }