drm/amd/display: Fix incorrect end slope of EETF

Force the E2 to dc_fixpt_one when E1 exceeds that value. This is the
correct thing to do to avoid corruption.

Signed-off-by: SivapiriyanKumarasamy <sivapiriyan.kumarasamy@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
index 2e215c9..bba5186 100644 (file)
--- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
+++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
@@ -789,7 +789,8 @@ static void hermite_spline_eetf(struct fixed31_32 input_x,
                // (t^3 - 2t^2 + t) * (1-ks)
                E2 = dc_fixpt_add(E2, dc_fixpt_mul(temp2,
                                dc_fixpt_add(t, dc_fixpt_sub(t3, temp1))));
-       }
+       } else
+               E2 = dc_fixpt_one;
 
        temp1 = dc_fixpt_sub(dc_fixpt_one, E2);
        temp2 = dc_fixpt_mul(temp1, temp1);