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@xxxxxxxxxxxxx/ Fixes: 8b25320887d7 ("drm: Add fixed-point helper to get rounded integer values") Suggested-by: Pekka Paalanen <pekka.paalanen@xxxxxxxxxxxxx> Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx> Signed-off-by: Arthur Grillo <arthurgrillo@xxxxxxxxxx> --- Changes in v2: - Add Fixes tag (Melissa Wen) - Remove DRM_FIXED_POINT_HALF (Melissa Wen) - Link to v1: https://lore.kernel.org/all/20240306-louis-vkms-conv-v1-1-5bfe7d129fdd@xxxxxxxxxx/ --- include/drm/drm_fixed.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/include/drm/drm_fixed.h b/include/drm/drm_fixed.h index 0c9f917a4d4b..81572d32db0c 100644 --- a/include/drm/drm_fixed.h +++ b/include/drm/drm_fixed.h @@ -71,7 +71,6 @@ static inline u32 dfixed_div(fixed20_12 A, fixed20_12 B) } #define DRM_FIXED_POINT 32 -#define DRM_FIXED_POINT_HALF 16 #define DRM_FIXED_ONE (1ULL << DRM_FIXED_POINT) #define DRM_FIXED_DECIMAL_MASK (DRM_FIXED_ONE - 1) #define DRM_FIXED_DIGITS_MASK (~DRM_FIXED_DECIMAL_MASK) @@ -90,7 +89,7 @@ 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) --- base-commit: f89632a9e5fa6c4787c14458cd42a9ef42025434 change-id: 20240315-drm_fixed-c680ba078ecb Best regards, -- Arthur Grillo <arthurgrillo@xxxxxxxxxx>
