drm/amd/display: Use fixed DET Buffer Size

[why]
Regression from DML1.0 where we use differen DET buffer sizes for each
pipe. From the spec, we need to use DET buffer size of 384 kb for each
pipe

[how]
Ensure to use 384 kb DET buffer sizes for each available pipe.
Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Sung Joon Kim <sungkim@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn35/dcn35_resource.c

@@ -2078,7 +2078,8 @@ static bool dcn35_resource_construct(
 	dc->dml2_options.callbacks.build_scaling_params = &resource_build_scaling_params;
 	dc->dml2_options.callbacks.can_support_mclk_switch_using_fw_based_vblank_stretch = &dcn30_can_support_mclk_switch_using_fw_based_vblank_stretch;
 	dc->dml2_options.callbacks.acquire_secondary_pipe_for_mpc_odm = &dc_resource_acquire_secondary_pipe_for_mpc_odm_legacy;
-	dc->dml2_options.max_segments_per_hubp = 18;
+	dc->dml2_options.max_segments_per_hubp = 24;
+
 	dc->dml2_options.det_segment_size = DCN3_2_DET_SEG_SIZE;/*todo*/
 
 	if (dc->config.sdpif_request_limit_words_per_umc == 0)

drivers/gpu/drm/amd/display/dc/dml2/dml2_utils.c

@@ -414,17 +414,21 @@ void dml2_apply_det_buffer_allocation_policy(struct dml2_context *in_ctx, struct
 
 	for (plane_index = 0; plane_index < dml_dispcfg->num_surfaces; plane_index++) {
 
-		dml_dispcfg->plane.DETSizeOverride[plane_index] = ((max_det_size / num_of_streams) / num_of_planes_per_stream[stream_index] / in_ctx->det_helper_scratch.dpps_per_surface[plane_index]);
+		if (in_ctx->config.override_det_buffer_size_kbytes)
+			dml_dispcfg->plane.DETSizeOverride[plane_index] = max_det_size / in_ctx->config.dcn_pipe_count;
+		else {
+			dml_dispcfg->plane.DETSizeOverride[plane_index] = ((max_det_size / num_of_streams) / num_of_planes_per_stream[stream_index] / in_ctx->det_helper_scratch.dpps_per_surface[plane_index]);
+
+			/* If the override size is not divisible by det_segment_size then round off to nearest number divisible by det_segment_size as
+				* this is a requirement.
+				*/
+			if (dml_dispcfg->plane.DETSizeOverride[plane_index] % in_ctx->config.det_segment_size != 0) {
+				dml_dispcfg->plane.DETSizeOverride[plane_index] = dml_dispcfg->plane.DETSizeOverride[plane_index] & ~0x3F;
+			}
 
-		/* If the override size is not divisible by det_segment_size then round off to nearest number divisible by det_segment_size as
-		 * this is a requirement.
-		 */
-		if (dml_dispcfg->plane.DETSizeOverride[plane_index] % in_ctx->config.det_segment_size != 0) {
-			dml_dispcfg->plane.DETSizeOverride[plane_index] = dml_dispcfg->plane.DETSizeOverride[plane_index] & ~0x3F;
+			if (plane_index + 1 < dml_dispcfg->num_surfaces && dml_dispcfg->plane.BlendingAndTiming[plane_index] != dml_dispcfg->plane.BlendingAndTiming[plane_index + 1])
+				stream_index++;
 		}
-
-		if (plane_index + 1 < dml_dispcfg->num_surfaces && dml_dispcfg->plane.BlendingAndTiming[plane_index] != dml_dispcfg->plane.BlendingAndTiming[plane_index + 1])
-			stream_index++;
 	}
 }
 

drivers/gpu/drm/amd/display/dc/dml2/dml2_wrapper.h

@@ -137,6 +137,7 @@ struct dml2_configuration_options {
 	bool skip_hw_state_mapping;
 	bool optimize_odm_4to1;
 	bool minimize_dispclk_using_odm;
+	bool override_det_buffer_size_kbytes;
 	struct dml2_dc_callbacks callbacks;
 	struct {
 		bool force_disable_subvp;