Re: [Outreachy kernel] [PATCH 2/3] staging: iio: dummy: add the timestamp buffer to the scan index enum

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Oct 26, 2015 at 01:49:35PM -0700, Alison Schofield wrote:
> Replace the hard coded buffer index for IIO_CHAN SOFT_TIMESTAMP with
> an entry in the scan index enum.
> 
> Signed-off-by: Alison Schofield <amsfield22@gmail.com>
> ---
>  drivers/staging/iio/iio_simple_dummy.c        | 6 +++---
>  drivers/staging/iio/iio_simple_dummy.h        | 2 ++
>  drivers/staging/iio/iio_simple_dummy_buffer.c | 1 +
>  3 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/staging/iio/iio_simple_dummy.c b/drivers/staging/iio/iio_simple_dummy.c
> index 70a82cd..2749746 100644
> --- a/drivers/staging/iio/iio_simple_dummy.c
> +++ b/drivers/staging/iio/iio_simple_dummy.c
> @@ -230,10 +230,10 @@ static const struct iio_chan_spec iio_dummy_channels[] = {
>  		},
>  	},
>  	/*
> -	 * Convenience macro for timestamps. 4 is the index in
> -	 * the buffer.
> +	 * Convenience macro for timestamps.
> +	 * DUMMY_INDEX_TIMESTAMP is the index in the buffer.
>  	 */
> -	IIO_CHAN_SOFT_TIMESTAMP(4),
> +	IIO_CHAN_SOFT_TIMESTAMP(DUMMY_INDEX_TIMESTAMP),
>  	/* DAC channel out_voltage0_raw */
>  	{
>  		.type = IIO_VOLTAGE,
> diff --git a/drivers/staging/iio/iio_simple_dummy.h b/drivers/staging/iio/iio_simple_dummy.h
> index b9069a1..89fb650 100644
> --- a/drivers/staging/iio/iio_simple_dummy.h
> +++ b/drivers/staging/iio/iio_simple_dummy.h
> @@ -102,6 +102,7 @@ iio_simple_dummy_events_unregister(struct iio_dev *indio_dev)
>   * @DUMMY_INDEX_DIFFVOLTAGE_1M2:   first differential channel
>   * @DUMMY_INDEX_DIFFVOLTAGE_3M4:   second differential channel
>   * @DUMMY_INDEX_ACCELX:            acceleration channel
> + * @DUMMY_INDEX_TIMESTAMP:         timestamp channel
>   *
>   * Enum provides convenient numbering for the scan index.
>   */
> @@ -110,6 +111,7 @@ enum iio_simple_dummy_scan_elements {
>  	DUMMY_INDEX_DIFFVOLTAGE_1M2,
>  	DUMMY_INDEX_DIFFVOLTAGE_3M4,
>  	DUMMY_INDEX_ACCELX,
> +	DUMMY_INDEX_TIMESTAMP,
>  };
>  
>  #ifdef CONFIG_IIO_SIMPLE_DUMMY_BUFFER
> diff --git a/drivers/staging/iio/iio_simple_dummy_buffer.c b/drivers/staging/iio/iio_simple_dummy_buffer.c
> index cf44a6f..eea3e76 100644
> --- a/drivers/staging/iio/iio_simple_dummy_buffer.c
> +++ b/drivers/staging/iio/iio_simple_dummy_buffer.c
> @@ -31,6 +31,7 @@ static const s16 fakedata[] = {
>  	[DUMMY_INDEX_DIFFVOLTAGE_1M2] = -33,
>  	[DUMMY_INDEX_DIFFVOLTAGE_3M4] = -2,
>  	[DUMMY_INDEX_ACCELX] = 344,
> +	[DUMMY_INDEX_TIMESTAMP] = 50,

You just increased the size of this structure, why?