Re: [PATCH v2 1/2] iio: core: Forbid use of both labels and extended names

[Alexandru Ardelean]

On Wed, Jun 16, 2021 at 7:01 PM Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote:
>
> Extended names are a problem for user-space as they make the filenames
> in sysfs sometimes not parsable. They are now deprecated in favor of
> labels.
>
> This change makes sure that a device driver won't provide both labels
> and extended names for its channels. It has never been the case and we
> don't want it to happen.
>

Reviewed-by: Alexandru Ardelean <ardeleanalex@xxxxxxxxx>

> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> ---
>  drivers/iio/industrialio-core.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
>
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 59efb36db2c7..81f40dab778a 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1836,6 +1836,24 @@ static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
>         return 0;
>  }
>
> +static int iio_check_extended_name(const struct iio_dev *indio_dev)
> +{
> +       unsigned int i;
> +
> +       if (!indio_dev->info->read_label)
> +               return 0;
> +
> +       for (i = 0; i < indio_dev->num_channels; i++) {
> +               if (indio_dev->channels[i].extend_name) {
> +                       dev_err(&indio_dev->dev,
> +                               "Cannot use labels and extend_name at the same time\n");
> +                       return -EINVAL;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
>  static const struct iio_buffer_setup_ops noop_ring_setup_ops;
>
>  int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
> @@ -1860,6 +1878,10 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
>         if (ret < 0)
>                 return ret;
>
> +       ret = iio_check_extended_name(indio_dev);
> +       if (ret < 0)
> +               return ret;
> +
>         iio_device_register_debugfs(indio_dev);
>
>         ret = iio_buffers_alloc_sysfs_and_mask(indio_dev);
> --
> 2.30.2
>