Commit 0b553f85 authored Aug 22, 2022 by Yao Wang1 Committed by Greg Kroah-Hartman Sep 28, 2022

drm/amd/display: Limit user regamma to a valid value



[ Upstream commit 3601d620f22e37740cf73f8278eabf9f2aa19eb7 ]

[Why]
For HDR mode, we get total 512 tf_point and after switching to SDR mode
we actually get 400 tf_point and the rest of points(401~512) still use
dirty value from HDR mode. We should limit the rest of the points to max
value.

[How]
Limit the value when coordinates_x.x > 1, just like what we do in
translate_from_linear_space for other re-gamma build paths.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: Yao Wang1 <Yao.Wang1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent c3f8c7e9

drivers/gpu/drm/amd/display/modules/color/color_gamma.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1206,6 +1206,7 @@ static void interpolate_user_regamma(uint32_t hw_points_num,
		struct fixed31_32 lut2;
		struct fixed31_32 delta_lut;
		struct fixed31_32 delta_index;
		const struct fixed31_32 one = dc_fixpt_from_int(1);

		i = 0;
		/* fixed_pt library has problems handling too small values */
		@@ -1234,6 +1235,9 @@ static void interpolate_user_regamma(uint32_t hw_points_num,
		} else
		hw_x = coordinates_x[i].x;

		if (dc_fixpt_le(one, hw_x))
		hw_x = one;

		norm_x = dc_fixpt_mul(norm_factor, hw_x);
		index = dc_fixpt_floor(norm_x);
		if (index < 0 \|\| index > 255)