drm/amd/display: SubVP missing scaling case

[Description]
For SubVP scaling case we have to combine
the plane scaling and stream scaling.

Use UCLK dummy p-state WM for FCLK WM set C

[Description]
For DCN32/321 program dummy UCLK P-state watermark into FCLK
watermark set C register.
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Reviewed-by: Nevenko Stupar <Nevenko.Stupar@amd.com>
Acked-by: Brian Chang <Brian.Chang@amd.com>
Signed-off-by: Alvin Lee <Alvin.Lee2@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c

@@ -634,7 +634,7 @@ static void populate_subvp_cmd_pipe_info(struct dc *dc,
 			&cmd->fw_assisted_mclk_switch_v2.config_data.pipe_data[cmd_pipe_index];
 	struct dc_crtc_timing *main_timing = &subvp_pipe->stream->timing;
 	struct dc_crtc_timing *phantom_timing = &subvp_pipe->stream->mall_stream_config.paired_stream->timing;
-	uint32_t out_num, out_den;
+	uint32_t out_num_stream, out_den_stream, out_num_plane, out_den_plane, out_num, out_den;
 
 	pipe_data->mode = SUBVP;
 	pipe_data->pipe_config.subvp_data.pix_clk_100hz = subvp_pipe->stream->timing.pix_clk_100hz;
@@ -651,8 +651,14 @@ static void populate_subvp_cmd_pipe_info(struct dc *dc,
 	/* Calculate the scaling factor from the src and dst height.
 	 * e.g. If 3840x2160 being downscaled to 1920x1080, the scaling factor is 1/2.
 	 * Reduce the fraction 1080/2160 = 1/2 for the "scaling factor"
+	 *
+	 * Make sure to combine stream and plane scaling together.
 	 */
-	reduce_fraction(subvp_pipe->stream->src.height, subvp_pipe->stream->dst.height, &out_num, &out_den);
+	reduce_fraction(subvp_pipe->stream->src.height, subvp_pipe->stream->dst.height,
+			&out_num_stream, &out_den_stream);
+	reduce_fraction(subvp_pipe->plane_state->src_rect.height, subvp_pipe->plane_state->dst_rect.height,
+			&out_num_plane, &out_den_plane);
+	reduce_fraction(out_num_stream * out_num_plane, out_den_stream * out_den_plane, &out_num, &out_den);
 	pipe_data->pipe_config.subvp_data.scale_factor_numerator = out_num;
 	pipe_data->pipe_config.subvp_data.scale_factor_denominator = out_den;
 

drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c

@@ -1796,7 +1796,11 @@ void dcn32_calculate_wm_and_dlg_fpu(struct dc *dc, struct dc_state *context,
 	context->bw_ctx.bw.dcn.watermarks.c.frac_urg_bw_nom = get_fraction_of_urgent_bandwidth(&context->bw_ctx.dml, pipes, pipe_cnt) * 1000;
 	context->bw_ctx.bw.dcn.watermarks.c.frac_urg_bw_flip = get_fraction_of_urgent_bandwidth_imm_flip(&context->bw_ctx.dml, pipes, pipe_cnt) * 1000;
 	context->bw_ctx.bw.dcn.watermarks.c.urgent_latency_ns = get_urgent_latency(&context->bw_ctx.dml, pipes, pipe_cnt) * 1000;
-	context->bw_ctx.bw.dcn.watermarks.c.cstate_pstate.fclk_pstate_change_ns = get_fclk_watermark(&context->bw_ctx.dml, pipes, pipe_cnt) * 1000;
+	/* On DCN32/321, PMFW will set PSTATE_CHANGE_TYPE = 1 (FCLK) for UCLK dummy p-state.
+	 * In this case we must program FCLK WM Set C to use the UCLK dummy p-state WM
+	 * value.
+	 */
+	context->bw_ctx.bw.dcn.watermarks.c.cstate_pstate.fclk_pstate_change_ns = get_wm_dram_clock_change(&context->bw_ctx.dml, pipes, pipe_cnt) * 1000;
 	context->bw_ctx.bw.dcn.watermarks.c.usr_retraining_ns = get_usr_retraining_watermark(&context->bw_ctx.dml, pipes, pipe_cnt) * 1000;
 
 	if ((!pstate_en) && (dc->clk_mgr->bw_params->wm_table.nv_entries[WM_C].valid)) {