From 9da4b39d83122eff3aa3d66d4613d4a8ba37274e Mon Sep 17 00:00:00 2001
From: Josip Pavic <Josip.Pavic@amd.com>
Date: Tue, 26 Nov 2019 12:26:14 -0500
Subject: drm/amd/display: fix regamma build optimization
Git-commit: d87dedb1eca506adbb2647e96615676c2915952b
Patch-mainline: v5.6-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
[Why]
When the global variable pow_buffer_ptr is set to -1, by definition
optimizations should not be used to build the regamma. Since
translate_from_linear_space unconditionally increments this global, it
inadvertently enables the optimization.
[How]
Increment pow_buffer_ptr only if it is not -1.
Signed-off-by: Josip Pavic <Josip.Pavic@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/modules/color/color_gamma.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
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 b52c4d379651..1b278c42809a 100644
--- a/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
+++ b/drivers/gpu/drm/amd/display/modules/color/color_gamma.c
@@ -364,8 +364,10 @@ static struct fixed31_32 translate_from_linear_space(
scratch_2 = dc_fixpt_mul(gamma_of_2,
pow_buffer[pow_buffer_ptr%16]);
- pow_buffer[pow_buffer_ptr%16] = scratch_2;
- pow_buffer_ptr++;
+ if (pow_buffer_ptr != -1) {
+ pow_buffer[pow_buffer_ptr%16] = scratch_2;
+ pow_buffer_ptr++;
+ }
scratch_1 = dc_fixpt_mul(scratch_1, scratch_2);
scratch_1 = dc_fixpt_sub(scratch_1, args->a2);
--
2.28.0