Re: [PATCH 2/2] iio:accel:bma180: Make LOW_PASS_FILTER_3DB_FREQUENCY shared_by_type

[Jonathan Cameron <jic23@kernel.org>]

On 10/01/14 21:37, Peter Meerwald wrote:
> the property is not per-channel, but shared by type
>
Now this one is in a sense even more interesting.

1) Your fix is correct.
2) Other than poluting sysfs with extra attributes and setting a bad
    example, it doesn't actually matter as any attribute is defined
    as being able to effect any other. e.g. if we had two different
    filters, one for the z axis and another effecting both x and y
    we would have to define all 3 as separate.
3) In theory correctly written generic userspace code should not care
    as it should handle both cases without a user being any the wiser.
    Hence this should fall into the category of being able to change
    userspace ABI if no one notices...

So what shall we do?
> Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
> Cc: Kravchenko Oleksandr <x0199363@ti.com>
> ---
>   drivers/iio/accel/bma180.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
> index bfec313..a7e68c8 100644
> --- a/drivers/iio/accel/bma180.c
> +++ b/drivers/iio/accel/bma180.c
> @@ -451,9 +451,9 @@ static const struct iio_chan_spec_ext_info bma180_ext_info[] = {
>   	.type = IIO_ACCEL,						\
>   	.modified = 1,							\
>   	.channel2 = IIO_MOD_##_axis,					\
> -	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
>   		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
> -	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
>   	.scan_index = AXIS_##_axis,					\
>   	.scan_type = {							\
>   		.sign = 's',						\
>