[PATCH v7 2/5] media: rkisp1: stats: remove a wrong cast to u8

[Dafna Hirschfeld]

Am 21.01.21 um 11:07 schrieb Tomasz Figa:
> Hi Dafna,
> 
> On Thu, Jan 21, 2021 at 1:45 AM Dafna Hirschfeld
> <dafna.hirschfeld at collabora.com> wrote:
>>
>> hist_bins is an array of type __u32. Each entry represent
>> a 20 bit fixed point value as documented inline.
>> The cast to u8 when setting the values is wrong. Remove it.
> 
> Thanks for the patch. See my comment inline.
> 
>>
>> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld at collabora.com>
>> ---
>>   drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c | 3 +--
>>   1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c
>> index 3ddab8fa8f2d..4cdb180fa64d 100644
>> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c
>> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-stats.c
>> @@ -235,8 +235,7 @@ static void rkisp1_stats_get_hst_meas(struct rkisp1_stats *stats,
>>          pbuf->meas_type |= RKISP1_CIF_ISP_STAT_HIST;
>>          for (i = 0; i < RKISP1_CIF_ISP_HIST_BIN_N_MAX; i++)
>>                  pbuf->params.hist.hist_bins[i] =
>> -                       (u8)rkisp1_read(rkisp1,
>> -                                       RKISP1_CIF_ISP_HIST_BIN_0 + i * 4);
>> +                       rkisp1_read(rkisp1, RKISP1_CIF_ISP_HIST_BIN_0 + i * 4);
> 
> Is the register guaranteed to return 0 for the upper unused 12 bits?
> Should we mask them instead?

I printed the values and I always see 0 for the last 12 bits. But the datasheet
does not say that explicitly.
I can add a mask to be on the safe side.

Thanks,
Dafna

> 
> Best regards,
> Tomasz
>