[PATCH 1/7] drm: Fix drm_fixp2int_round() making it add 0.5

Harry Wentland harry.wentland at amd.com
Fri Mar 8 20:57:00 UTC 2024


On 2024-03-06 15:03, Arthur Grillo wrote:
> As well noted by Pekka[1], the rounding of drm_fixp2int_round is wrong.
> To round a number, you need to add 0.5 to the number and floor that,
> drm_fixp2int_round() is adding 0.0000076. Make it add 0.5.
> 
> [1]: https://lore.kernel.org/all/20240301135327.22efe0dd.pekka.paalanen@collabora.com/
> 
> Suggested-by: Pekka Paalanen <pekka.paalanen at collabora.com>
> Signed-off-by: Arthur Grillo <arthurgrillo at riseup.net>

Reviewed-by: Harry Wentland <harry.wentland at amd.com>

I had a different jab at this [1], but your patch is cleaner.

https://patchwork.freedesktop.org/patch/579978/?series=123446&rev=4

Harry

> ---
>   include/drm/drm_fixed.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/drm/drm_fixed.h b/include/drm/drm_fixed.h
> index 0c9f917a4d4b..de3a79909ac9 100644
> --- a/include/drm/drm_fixed.h
> +++ b/include/drm/drm_fixed.h
> @@ -90,7 +90,7 @@ static inline int drm_fixp2int(s64 a)
>   
>   static inline int drm_fixp2int_round(s64 a)
>   {
> -	return drm_fixp2int(a + (1 << (DRM_FIXED_POINT_HALF - 1)));
> +	return drm_fixp2int(a + DRM_FIXED_ONE / 2);
>   }
>   
>   static inline int drm_fixp2int_ceil(s64 a)
> 


More information about the dri-devel mailing list