Re: [PATCH 1/3] iio: Always compute masklength

[Jonathan Cameron <jic23@kernel.org>]

On 29/05/15 17:14, Lars-Peter Clausen wrote:
> Even if no userspace consumer buffer is attached to the IIO device at
> registration we still need to compute the masklength, since it is possible
> that a in-kernel consumer buffer is going to get attached to the device at
> a later point.
> 
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Not sure we actually have this condition as of yet, but I guess it 'might'
occur.  Certainly would be good to allow for IIO devices without an
IIO 'front end' in the future.
> ---
>  drivers/iio/industrialio-buffer.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
> index 1129125..a72db00 100644
> --- a/drivers/iio/industrialio-buffer.c
> +++ b/drivers/iio/industrialio-buffer.c
> @@ -968,6 +968,15 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
>  	int ret, i, attrn, attrcount, attrcount_orig = 0;
>  	const struct iio_chan_spec *channels;
>  
> +	channels = indio_dev->channels;
> +	if (channels) {
> +		int ml = indio_dev->masklength;
> +
> +		for (i = 0; i < indio_dev->num_channels; i++)
> +			ml = max(ml, channels[i].scan_index + 1);
> +		indio_dev->masklength = ml;
> +	}
> +
>  	if (!buffer)
>  		return 0;
>  
> @@ -1011,12 +1020,6 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
>  			if (channels[i].scan_index < 0)
>  				continue;
>  
> -			/* Establish necessary mask length */
> -			if (channels[i].scan_index >
> -			    (int)indio_dev->masklength - 1)
> -				indio_dev->masklength
> -					= channels[i].scan_index + 1;
> -
>  			ret = iio_buffer_add_channel_sysfs(indio_dev,
>  							 &channels[i]);
>  			if (ret < 0)
>