[PATCH v7 1/5] media: rkisp1: uapi: change hist_bins array type from __u16 to __u32

[Sakari Ailus]

Hi Dafna,

Thanks for the update.

On Wed, Jan 20, 2021 at 05:44:42PM +0100, Dafna Hirschfeld wrote:
> Each entry in the array is a 20 bits value composed of 16
> bits unsigned integer and 4 bits fractional part. So the
> type should change to __u32.
> In addition add a documentation of how the measurements
> are done.

The commit message lines wrap at 74, under 60 is not much.

> 
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld at collabora.com>

Should there be a Fixes: line? The patch is changing UAPI...

The file has been recently introduced. Should it go to fixes or to a stable
kernel, too?

> ---
>  include/uapi/linux/rkisp1-config.h | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> index 6e449e784260..f75f8d698fb4 100644
> --- a/include/uapi/linux/rkisp1-config.h
> +++ b/include/uapi/linux/rkisp1-config.h
> @@ -844,13 +844,17 @@ struct rkisp1_cif_isp_af_stat {
>  /**
>   * struct rkisp1_cif_isp_hist_stat - statistics histogram data
>   *
> - * @hist_bins: measured bin counters
> + * @hist_bins: measured bin counters. Each bin is a 20 bits unsigned fixed point type.
> + *	       Bits 0-4 are the fractional part and bits 5-19 are the integer part.
>   *
> - * Measurement window divided into 25 sub-windows, set
> - * with ISP_HIST_XXX
> + * The window of the measurements area is divided to 5x5 sub-windows. The histogram
> + * is then computed for each sub-window independently and the final result is a weighted
> + * average of the histogram measurements on all sub-windows.
> + * The window of the measurements area and the weight of each sub-window are configurable
> + * using struct @rkisp1_cif_isp_hst_config.

Please wrap the lines before 80.

>   */
>  struct rkisp1_cif_isp_hist_stat {
> -	__u16 hist_bins[RKISP1_CIF_ISP_HIST_BIN_N_MAX];
> +	__u32 hist_bins[RKISP1_CIF_ISP_HIST_BIN_N_MAX];
>  };
>  
>  /**
> -- 
> 2.17.1
> 

-- 
Regards,

Sakari Ailus