On Thu, 12 Nov 2020 15:43:22 +0100
Nuno Sá <nuno.sa@xxxxxxxxxx> wrote:
> When updating the buffer demux, we will skip a scan element from the
> device in the case `in_ind != out_ind` and we enter the while loop.
> in_ind should only be refreshed with `find_next_bit()` in the end of the
> loop.
>
> Fixes: 5ada4ea9be16 ("staging:iio: add demux optionally to path from device to buffer")
> Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Yikes that's been there a long time.
Could you provide an example of a particular layout and the result of this being wrong?
Thanks,
Jonathan
> ---
> drivers/iio/industrialio-buffer.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
> index a4f6bb96d4f4..276b609d7917 100644
> --- a/drivers/iio/industrialio-buffer.c
> +++ b/drivers/iio/industrialio-buffer.c
> @@ -865,12 +865,12 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
> indio_dev->masklength,
> in_ind + 1);
> while (in_ind != out_ind) {
> - in_ind = find_next_bit(indio_dev->active_scan_mask,
> - indio_dev->masklength,
> - in_ind + 1);
> length = iio_storage_bytes_for_si(indio_dev, in_ind);
> /* Make sure we are aligned */
> in_loc = roundup(in_loc, length) + length;
> + in_ind = find_next_bit(indio_dev->active_scan_mask,
> + indio_dev->masklength,
> + in_ind + 1);
> }
> length = iio_storage_bytes_for_si(indio_dev, in_ind);
> out_loc = roundup(out_loc, length);
