Re: [PATCH 2/5] iio: temperature: mcp9600: Share scale by all channels

[Jonathan Cameron]

On Tue, 30 Apr 2024 14:05:32 +0200
Dimitri Fedrau <dima.fedrau@xxxxxxxxx> wrote:

> Move bit IIO_CHAN_INFO_SCALE from info_mask_separate to
> info_mask_shared_by_all since temperature format is the same for all
> channels.
> 
> Signed-off-by: Dimitri Fedrau <dima.fedrau@xxxxxxxxx>

Whilst this shouldn't be a problem for well behaved userspace,
it is an ABI change so as a general rule we don't 'fix' cases like
this once they have been in a kernel release.

We may be break someone's hand crafted scripts :(

Jonathan

> ---
>  drivers/iio/temperature/mcp9600.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/temperature/mcp9600.c b/drivers/iio/temperature/mcp9600.c
> index e277edb4ae4b..74e0782fb073 100644
> --- a/drivers/iio/temperature/mcp9600.c
> +++ b/drivers/iio/temperature/mcp9600.c
> @@ -28,16 +28,16 @@ static const struct iio_chan_spec mcp9600_channels[] = {
>  		.address = MCP9600_HOT_JUNCTION,
>  		.channel2 = IIO_MOD_TEMP_OBJECT,
>  		.modified = 1,
> -		.info_mask_separate =
> -			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE),
>  	},
>  	{
>  		.type = IIO_TEMP,
>  		.address = MCP9600_COLD_JUNCTION,
>  		.channel2 = IIO_MOD_TEMP_AMBIENT,
>  		.modified = 1,
> -		.info_mask_separate =
> -			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE),
>  	},
>  };
>