From: Arthur Grillo arthurgrillo@riseup.net
[ Upstream commit 807f96abdf14c80f534c78f2d854c2590963345c ]
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...
Fixes: 8b25320887d7 ("drm: Add fixed-point helper to get rounded integer values") Suggested-by: Pekka Paalanen pekka.paalanen@collabora.com Reviewed-by: Harry Wentland harry.wentland@amd.com Reviewed-by: Melissa Wen mwen@igalia.com Signed-off-by: Arthur Grillo arthurgrillo@riseup.net Signed-off-by: Melissa Wen melissa.srw@gmail.com Link: https://patchwork.freedesktop.org/patch/msgid/20240316-drm_fixed-v2-1-c1bc26... Signed-off-by: Sasha Levin sashal@kernel.org --- 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 0c9f917a4d4be..81572d32db0c2 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)