[PATCH 06/25] drm/amd/display: truncate scaling ratios and inits to 19 bit precision

[Harry Wentland]

From: Dmytro Laktyushkin <Dmytro.Laktyushkin at amd.com>

Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin at amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng at amd.com>
Acked-by: Harry Wentland <harry.wentland at amd.com>
---
 .../gpu/drm/amd/display/dc/core/dc_resource.c | 25 +++++++++++++------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 80aa8a63338f..e2ad6ed0bf42 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -656,6 +656,14 @@ static void calculate_scaling_ratios(struct pipe_ctx *pipe_ctx)
 		pipe_ctx->plane_res.scl_data.ratios.horz_c.value /= 2;
 		pipe_ctx->plane_res.scl_data.ratios.vert_c.value /= 2;
 	}
+	pipe_ctx->plane_res.scl_data.ratios.horz = dc_fixpt_truncate(
+			pipe_ctx->plane_res.scl_data.ratios.horz, 19);
+	pipe_ctx->plane_res.scl_data.ratios.vert = dc_fixpt_truncate(
+			pipe_ctx->plane_res.scl_data.ratios.vert, 19);
+	pipe_ctx->plane_res.scl_data.ratios.horz_c = dc_fixpt_truncate(
+			pipe_ctx->plane_res.scl_data.ratios.horz_c, 19);
+	pipe_ctx->plane_res.scl_data.ratios.vert_c = dc_fixpt_truncate(
+			pipe_ctx->plane_res.scl_data.ratios.vert_c, 19);
 }
 
 static void calculate_inits_and_adj_vp(struct pipe_ctx *pipe_ctx, struct view *recout_skip)
@@ -692,17 +700,18 @@ static void calculate_inits_and_adj_vp(struct pipe_ctx *pipe_ctx, struct view *r
 	 * 	init_bot = init + scaling_ratio
 	 * 	init_c = init + truncated_vp_c_offset(from calculate viewport)
 	 */
-	data->inits.h = dc_fixpt_div_int(
-			dc_fixpt_add_int(data->ratios.horz, data->taps.h_taps + 1), 2);
+	data->inits.h = dc_fixpt_truncate(dc_fixpt_div_int(
+			dc_fixpt_add_int(data->ratios.horz, data->taps.h_taps + 1), 2), 19);
 
-	data->inits.h_c = dc_fixpt_add(data->inits.h_c, dc_fixpt_div_int(
-			dc_fixpt_add_int(data->ratios.horz_c, data->taps.h_taps_c + 1), 2));
+	data->inits.h_c = dc_fixpt_truncate(dc_fixpt_add(data->inits.h_c, dc_fixpt_div_int(
+			dc_fixpt_add_int(data->ratios.horz_c, data->taps.h_taps_c + 1), 2)), 19);
 
-	data->inits.v = dc_fixpt_div_int(
-			dc_fixpt_add_int(data->ratios.vert, data->taps.v_taps + 1), 2);
+	data->inits.v = dc_fixpt_truncate(dc_fixpt_div_int(
+			dc_fixpt_add_int(data->ratios.vert, data->taps.v_taps + 1), 2), 19);
+
+	data->inits.v_c = dc_fixpt_truncate(dc_fixpt_add(data->inits.v_c, dc_fixpt_div_int(
+			dc_fixpt_add_int(data->ratios.vert_c, data->taps.v_taps_c + 1), 2)), 19);
 
-	data->inits.v_c = dc_fixpt_add(data->inits.v_c, dc_fixpt_div_int(
-			dc_fixpt_add_int(data->ratios.vert_c, data->taps.v_taps_c + 1), 2));
 
 
 	/* Adjust for viewport end clip-off */
-- 
2.17.0