Hi Niklas,
Thank you for the patch.
On Tuesday 06 Sep 2016 16:38:56 Niklas Söderlund wrote:
> The HGT is a Histogram Generator Two-Dimensions. It computes a weighted
> frequency histograms for hue and saturation areas over a configurable
> region of the image with optional subsampling.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> ---
> drivers/media/platform/vsp1/Makefile | 2 +-
> drivers/media/platform/vsp1/vsp1.h | 3 +
> drivers/media/platform/vsp1/vsp1_drv.c | 33 ++++-
> drivers/media/platform/vsp1/vsp1_entity.c | 33 +++--
> drivers/media/platform/vsp1/vsp1_entity.h | 1 +
> drivers/media/platform/vsp1/vsp1_hgt.c | 217 +++++++++++++++++++++++++++
> drivers/media/platform/vsp1/vsp1_hgt.h | 42 ++++++
> drivers/media/platform/vsp1/vsp1_pipe.c | 16 +++
> drivers/media/platform/vsp1/vsp1_pipe.h | 2 +
> drivers/media/platform/vsp1/vsp1_regs.h | 9 ++
> drivers/media/platform/vsp1/vsp1_video.c | 10 +-
> 11 files changed, 352 insertions(+), 16 deletions(-)
> create mode 100644 drivers/media/platform/vsp1/vsp1_hgt.c
> create mode 100644 drivers/media/platform/vsp1/vsp1_hgt.h
[snip]
> diff --git a/drivers/media/platform/vsp1/vsp1_hgt.c
> b/drivers/media/platform/vsp1/vsp1_hgt.c new file mode 100644
> index 0000000..4e3f762
> --- /dev/null
> +++ b/drivers/media/platform/vsp1/vsp1_hgt.c
[snip]
> +/* ------------------------------------------------------------------------
> + * Controls
> + */
> +
> +#define V4L2_CID_VSP1_HGT_HUE_AREAS (V4L2_CID_USER_BASE | 0x1001)
> +
> +static int hgt_hue_areas_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> + struct vsp1_hgt *hgt = container_of(ctrl->handler, struct vsp1_hgt,
> + ctrls);
> + u8 *value = ctrl->p_new.p_u8;
Nitpicking, I'd call the variable values.
> + unsigned int i;
> + bool ok = true;
> +
> + /*
> + * Make sure values meet one of two possible hardware constrains
s/constrains/constraints./
> + * 0L <= 0U <= 1L <= 1U <= 2L <= 2U <= 3L <= 3U <= 4L <= 4U <= 5L <=
5U
> + * 0U <= 1L <= 1U <= 2L <= 2U <= 3L <= 3U <= 4L <= 4U <= 5L <= 5U <=
0L
> + */
> +
> + if ((value[0] > value[1]) && (value[11] > value[0]))
> + ok = false;
> + for (i = 1; i < (HGT_NUM_HUE_AREAS * 2) - 1; ++i)
> + if (value[i] > value[i+1])
> + ok = false;
> +
> + /* Values do not match hardware, adjust to valid settings. */
> + if (!ok) {
> + for (i = 0; i < (HGT_NUM_HUE_AREAS * 2) - 1; ++i) {
> + if (value[i] > value[i+1])
> + value[i] = value[i+1];
> + }
> + }
I'm afraid this won't work. Let's assume value[0] = 100, value[1] = 50,
value[2] = 25. The loop will unroll to
if (value[0] /* 100 */ > value[1] /* 50 */)
value[0] = value[1] /* 50 */;
if (value[1] /* 50 */ > value[2] /* 25 */)
value[1] = value[2] /* 25 */;
You will end up with value[0] = 50, value[1] = 25, value[2] = 25, which
doesn't match the hardware constraints.
How about the following, which tests and fixes the values in a single
operation ?
static int hgt_hue_areas_s_ctrl(struct v4l2_ctrl *ctrl)
{
struct vsp1_hgt *hgt = container_of(ctrl->handler, struct vsp1_hgt,
ctrls);
u8 *values = ctrl->p_new.p_u8;
unsigned int i;
/*
* Adjust the values if they don't meet the hardware constraints:
*
* 0U <= 1L <= 1U <= 2L <= 2U <= 3L <= 3U <= 4L <= 4U <= 5L <= 5U
*/
for (i = 1; i < (HGT_NUM_HUE_AREAS * 2) - 1; ++i) {
if (values[i] > values[i+1])
values[i+1] = values[i];
}
/* 0L <= 0U or 5U <= 0L */
if (values[0] > values[1] && values[11] > values[0])
values[0] = values[1];
memcpy(hgt->hue_areas, ctrl->p_new.p_u8, sizeof(hgt->hue_areas));
return 0;
}
I'm also beginning to wonder whether it wouldn't make sense to return -EINVAL
when the values don't match the constraints instead of trying to fix them.
> + memcpy(hgt->hue_areas, ctrl->p_new.p_u8, sizeof(hgt->hue_areas));
> +
> + return 0;
> +}
[snip]
--
Regards,
Laurent Pinchart
