Re: [PATCH] media: stm32: dcmipp: pixelproc: Round up the compose lower bound

[Alain Volmat <alain.volmat@foss.st.com>]

Hi David,

thanks for the patch.

On Sun, Oct 18, 2026 at 04:20:11AM +0100, David Carlier wrote:
> The minimum compose size is crop / 64, rounded down. A 17 pixel compose
> on an 1100 pixel crop then needs four decimation steps, which overflows
> the 2-bit HDEC and VDEC fields in PxDCCR. Round the minimum up instead.
> 
> Fixes: 239cf9e5fda1 ("media: stm32: dcmipp: pixelproc: addition of dcmipp-pixelproc subdev")
> Signed-off-by: David Carlier <devnexen@gmail.com>
> ---
>  .../media/platform/st/stm32/stm32-dcmipp/dcmipp-pixelproc.c   | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-pixelproc.c b/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-pixelproc.c
> index 7d8e5f0863bf..9055682481de 100644
> --- a/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-pixelproc.c
> +++ b/drivers/media/platform/st/stm32/stm32-dcmipp/dcmipp-pixelproc.c
> @@ -597,10 +597,10 @@ static int dcmipp_pixelproc_set_selection(struct v4l2_subdev *sd,
>  		s->r.top = 0;
>  		s->r.left = 0;
>  		s->r.width = clamp_t(u32, s->r.width,
> -				     crop->width / DCMIPP_MAX_DOWNSCALE_RATIO,
> +				     DIV_ROUND_UP(crop->width, DCMIPP_MAX_DOWNSCALE_RATIO),
>  				     crop->width);
>  		s->r.height = clamp_t(u32, s->r.height,
> -				      crop->height / DCMIPP_MAX_DOWNSCALE_RATIO,
> +				      DIV_ROUND_UP(crop->height, DCMIPP_MAX_DOWNSCALE_RATIO),
>  				      crop->height);
>  		v4l2_rect_set_min_size(&s->r, &min_rect);
>  		*compose = s->r;

Acked-by: Alain Volmat <alain.volmat@foss.st.com>

Regards,
Alain

> -- 
> 2.55.0
>