As mentioned and discussed in [1] extend_name should not be used for full channel labels (and most drivers seem to only use it to express a short type of a channel) as this affects sysfs filenames, while the label name is supposed to be extracted from the *_label sysfs file instead. This appears to have been unclear to some drivers as extend_name is also used when read_label is unset, achieving an initial goal of providing sensible names in *_label sysfs files without noticing that sysfs filenames are (negatively and likely unintentionally) affected as well. Point readers of iio_chan_spec::extend_name to iio_info::read_label by mentioning deprecation and side-effects of this field. [1]: https://lore.kernel.org/linux-arm-msm/20221221223432.si2aasbleiicayfl@xxxxxxxxxxxxxx/ Suggested-by: Jonathan Cameron <jic23@xxxxxxxxxx> Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx> --- include/linux/iio/iio.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 81413cd3a3e7a..6fc06063505a7 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -221,6 +221,9 @@ struct iio_event_spec { * @extend_name: Allows labeling of channel attributes with an * informative name. Note this has no effect codes etc, * unlike modifiers. + * This field is deprecated in favour of providing + * iio_info->read_label() to override the label, which + * unlike @extend_name does not affect sysfs filenames. * @datasheet_name: A name used in in-kernel mapping of channels. It should * correspond to the first name that the channel is referred * to by in the datasheet (e.g. IND), or the nearest -- 2.40.1
