drm/amd/display: change zstate allow msg condition

[Why]
PMFW message which previously thought to only control Z9 controls both
Z9 and Z10. Also HW design team requested that Z9 must only be supported
on eDP due to content protection interop.

[How]
Change zstate support condition to match updated policy

Reviewed-by: Nicholas Kazlauskas <[e-mail]>
Acked-by: Rodrigo Siqueira <[e-mail]>
Signed-off-by: Eric Yang <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn31/dcn31_clk_mgr.c

···
 	 * also if safe to lower is false, we just go in the higher state
 	 */
 	if (safe_to_lower) {
-		if (new_clocks->z9_support == DCN_Z9_SUPPORT_ALLOW &&
-				new_clocks->z9_support != clk_mgr_base->clks.z9_support) {
+		if (new_clocks->zstate_support == DCN_ZSTATE_SUPPORT_ALLOW &&
+				new_clocks->zstate_support != clk_mgr_base->clks.zstate_support) {
 			dcn31_smu_set_Z9_support(clk_mgr, true);
-			clk_mgr_base->clks.z9_support = new_clocks->z9_support;
+			clk_mgr_base->clks.zstate_support = new_clocks->zstate_support;
 		}
 
 		if (clk_mgr_base->clks.dtbclk_en && !new_clocks->dtbclk_en) {
···
 			}
 		}
 	} else {
-		if (new_clocks->z9_support == DCN_Z9_SUPPORT_DISALLOW &&
-				new_clocks->z9_support != clk_mgr_base->clks.z9_support) {
+		if (new_clocks->zstate_support == DCN_ZSTATE_SUPPORT_DISALLOW &&
+				new_clocks->zstate_support != clk_mgr_base->clks.zstate_support) {
 			dcn31_smu_set_Z9_support(clk_mgr, false);
-			clk_mgr_base->clks.z9_support = new_clocks->z9_support;
+			clk_mgr_base->clks.zstate_support = new_clocks->zstate_support;
 		}
 
 		if (!clk_mgr_base->clks.dtbclk_en && new_clocks->dtbclk_en) {
···
 	clk_mgr->clks.p_state_change_support = true;
 	clk_mgr->clks.prev_p_state_change_support = true;
 	clk_mgr->clks.pwr_state = DCN_PWR_STATE_UNKNOWN;
-	clk_mgr->clks.z9_support = DCN_Z9_SUPPORT_UNKNOWN;
+	clk_mgr->clks.zstate_support = DCN_ZSTATE_SUPPORT_UNKNOWN;
 }
 
 static bool dcn31_are_clock_states_equal(struct dc_clocks *a,
···
 		return false;
 	else if (a->dcfclk_deep_sleep_khz != b->dcfclk_deep_sleep_khz)
 		return false;
-	else if (a->z9_support != b->z9_support)
+	else if (a->zstate_support != b->zstate_support)
 		return false;
 	else if (a->dtbclk_en != b->dtbclk_en)
 		return false;

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

···
 };
 
 #if defined(CONFIG_DRM_AMD_DC_DCN)
-enum dcn_z9_support_state {
-	DCN_Z9_SUPPORT_UNKNOWN,
-	DCN_Z9_SUPPORT_ALLOW,
-	DCN_Z9_SUPPORT_DISALLOW,
+enum dcn_zstate_support_state {
+	DCN_ZSTATE_SUPPORT_UNKNOWN,
+	DCN_ZSTATE_SUPPORT_ALLOW,
+	DCN_ZSTATE_SUPPORT_DISALLOW,
 };
 #endif
 /*
···
 	int dramclk_khz;
 	bool p_state_change_support;
 #if defined(CONFIG_DRM_AMD_DC_DCN)
-	enum dcn_z9_support_state z9_support;
+	enum dcn_zstate_support_state zstate_support;
 	bool dtbclk_en;
 #endif
 	enum dcn_pwr_state pwr_state;

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c

···
 	return false;
 }
 
+static enum dcn_zstate_support_state  decide_zstate_support(struct dc *dc, struct dc_state *context)
+{
+	int plane_count;
+	int i;
+
+	plane_count = 0;
+	for (i = 0; i < dc->res_pool->pipe_count; i++) {
+		if (context->res_ctx.pipe_ctx[i].plane_state)
+			plane_count++;
+	}
+
+	/*
+	 * Zstate is allowed in following scenarios:
+	 * 	1. Single eDP with PSR enabled
+	 * 	2. 0 planes (No memory requests)
+	 * 	3. Single eDP without PSR but > 5ms stutter period
+	 */
+	if (plane_count == 0)
+		return DCN_ZSTATE_SUPPORT_ALLOW;
+	else if (context->stream_count == 1 &&  context->streams[0]->signal == SIGNAL_TYPE_EDP) {
+		struct dc_link *link = context->streams[0]->sink->link;
+
+		if ((link->link_index == 0 && link->psr_settings.psr_feature_enabled)
+				|| context->bw_ctx.dml.vba.StutterPeriod > 5000.0)
+			return DCN_ZSTATE_SUPPORT_ALLOW;
+		else
+			return DCN_ZSTATE_SUPPORT_DISALLOW;
+	} else
+		return DCN_ZSTATE_SUPPORT_DISALLOW;
+}
+
 void dcn20_calculate_dlg_params(
 		struct dc *dc, struct dc_state *context,
 		display_e2e_pipe_params_st *pipes,
···
 		int vlevel)
 {
 	int i, pipe_idx;
-	int plane_count;
 
 	/* Writeback MCIF_WB arbitration parameters */
 	dc->res_pool->funcs->set_mcif_arb_params(dc, context, pipes, pipe_cnt);
···
 							!= dm_dram_clock_change_unsupported;
 	context->bw_ctx.bw.dcn.clk.dppclk_khz = 0;
 
-	context->bw_ctx.bw.dcn.clk.z9_support = (context->bw_ctx.dml.vba.StutterPeriod > 5000.0) ?
-			DCN_Z9_SUPPORT_ALLOW : DCN_Z9_SUPPORT_DISALLOW;
-
-	plane_count = 0;
-	for (i = 0; i < dc->res_pool->pipe_count; i++) {
-		if (context->res_ctx.pipe_ctx[i].plane_state)
-			plane_count++;
-	}
-
-	if (plane_count == 0)
-		context->bw_ctx.bw.dcn.clk.z9_support = DCN_Z9_SUPPORT_ALLOW;
+	context->bw_ctx.bw.dcn.clk.zstate_support = decide_zstate_support(dc, context);
 
 	context->bw_ctx.bw.dcn.clk.dtbclk_en = is_dtbclk_required(dc, context);