drm/amd/display: If P-State is supported try SubVP for smaller vlevel

[Description]
- To reduce vlevel further, we can try to apply subvp on
  configs that already support p-state since the natural
  p-state support may not allow for DPM0.
- Add code to try subvp to reduce UCLK DPM level further
  if already supported, but don't use subvp if it does not
  optimize the DPM level even lower
Reviewed-by: Samson Tam <samson.tam@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1416,6 +1416,7 @@ static void dcn32_full_validate_bw_helper(struct dc *dc,
 	unsigned int dc_pipe_idx = 0;
 	int i = 0;
 	bool found_supported_config = false;
+	int vlevel_temp = 0;
 
 	dc_assert_fp_enabled();
 
@@ -1448,13 +1449,15 @@ static void dcn32_full_validate_bw_helper(struct dc *dc,
 	 */
 	if (!dc->debug.force_disable_subvp && !dc->caps.dmub_caps.gecc_enable && dcn32_all_pipes_have_stream_and_plane(dc, context) &&
 	    !dcn32_mpo_in_use(context) && !dcn32_any_surfaces_rotated(dc, context) && !is_test_pattern_enabled(context) &&
-		(*vlevel == context->bw_ctx.dml.soc.num_states ||
+		(*vlevel == context->bw_ctx.dml.soc.num_states || (vba->DRAMSpeedPerState[*vlevel] != vba->DRAMSpeedPerState[0] &&
+				vba->DRAMClockChangeSupport[*vlevel][vba->maxMpcComb] != dm_dram_clock_change_unsupported) ||
 	    vba->DRAMClockChangeSupport[*vlevel][vba->maxMpcComb] == dm_dram_clock_change_unsupported ||
 	    dc->debug.force_subvp_mclk_switch)) {
 
 		dcn32_merge_pipes_for_subvp(dc, context);
 		memset(merge, 0, MAX_PIPES * sizeof(bool));
 
+		vlevel_temp = *vlevel;
 		/* to re-initialize viewport after the pipe merge */
 		for (i = 0; i < dc->res_pool->pipe_count; i++) {
 			struct pipe_ctx *pipe_ctx = &context->res_ctx.pipe_ctx[i];
@@ -1523,6 +1526,9 @@ static void dcn32_full_validate_bw_helper(struct dc *dc,
 			}
 		}
 
+		if (vba->DRAMSpeedPerState[*vlevel] >= vba->DRAMSpeedPerState[vlevel_temp])
+			found_supported_config = false;
+
 		// If SubVP pipe config is unsupported (or cannot be used for UCLK switching)
 		// remove phantom pipes and repopulate dml pipes
 		if (!found_supported_config) {