Re: [PATCH AUTOSEL 5.10 14/36] media: rkisp1: uapi: change hist_bins array type from __u16 to __u32
From: Hans Verkuil <hidden>
Date: 2021-02-08 21:36:57
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linux-media, lkml
On 08/02/2021 18:57, Sasha Levin wrote:
From: Dafna Hirschfeld <redacted> [ Upstream commit 31f190e0ccac8b75d33fdc95a797c526cf9b149e ] 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.
Dafna, Helen, does it make sense at all to backport these three patches to when rkisp1 was a staging driver? I would be inclined not to backport this. Regards, Hans
quoted hunk ↗ jump to hunk
Signed-off-by: Dafna Hirschfeld <redacted> Acked-by: Helen Koike <redacted> Signed-off-by: Hans Verkuil <redacted> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/staging/media/rkisp1/uapi/rkisp1-config.h | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)diff --git a/drivers/staging/media/rkisp1/uapi/rkisp1-config.h b/drivers/staging/media/rkisp1/uapi/rkisp1-config.h index 432cb6be55b47..c19fe059c2442 100644 --- a/drivers/staging/media/rkisp1/uapi/rkisp1-config.h +++ b/drivers/staging/media/rkisp1/uapi/rkisp1-config.h@@ -848,13 +848,18 @@ 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. */ 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]; }; /**