Re: [PATCH AUTOSEL 5.10 14/36] media: rkisp1: uapi: change hist_bins array type from __u16 to __u32

[Dafna Hirschfeld]

Am 08.02.21 um 21:46 schrieb Hans Verkuil:
> On 08/02/2021 18:57, Sasha Levin wrote:
> > From: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
> >
> > [ 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.

I also don't think it makes sense since this changes the uapi and it is not really a bug fix.


Thanks,
Dafna

> Regards,
>
> 	Hans
>
> > Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
> > Acked-by: Helen Koike <helen.koike@xxxxxxxxxxxxx>
> > Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
> > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> > ---
> >   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];
> >   };
> >   
> >   /**