drm/amd/display: Send DISPLAY_OFF after power down on boot

[WHY]
update_clocks might not be called on headless adapters. This means
DISPLAY_OFF may not be sent in headless cases.

[HOW]
If hardware is powered down on boot because it is headless (mode set
does not happen on that adapter) also send DISPLAY_OFF notification.
Signed-off-by: Sung Lee <sung.lee@amd.com>
Reviewed-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: Eryk Brol <eryk.brol@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c

@@ -94,6 +94,15 @@ int rn_get_active_display_cnt_wa(
 	return display_count;
 }
 
+void rn_set_low_power_state(struct clk_mgr *clk_mgr_base)
+{
+	struct clk_mgr_internal *clk_mgr = TO_CLK_MGR_INTERNAL(clk_mgr_base);
+
+	rn_vbios_smu_set_dcn_low_power_state(clk_mgr, DCN_PWR_STATE_LOW_POWER);
+	/* update power state */
+	clk_mgr_base->clks.pwr_state = DCN_PWR_STATE_LOW_POWER;
+}
+
 void rn_update_clocks(struct clk_mgr *clk_mgr_base,
 			struct dc_state *context,
 			bool safe_to_lower)
@@ -516,6 +525,7 @@ static struct clk_mgr_funcs dcn21_funcs = {
 	.init_clocks = rn_init_clocks,
 	.enable_pme_wa = rn_enable_pme_wa,
 	.are_clock_states_equal = rn_are_clock_states_equal,
+	.set_low_power_state = rn_set_low_power_state,
 	.notify_wm_ranges = rn_notify_wm_ranges,
 	.notify_link_rate_change = rn_notify_link_rate_change,
 };

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c

@@ -1450,33 +1450,42 @@ void dcn10_init_hw(struct dc *dc)
 void dcn10_power_down_on_boot(struct dc *dc)
 {
 	int i = 0;
+	struct dc_link *edp_link;
 
-	if (dc->config.power_down_display_on_boot) {
-		struct dc_link *edp_link = get_edp_link(dc);
-
-		if (edp_link &&
-				edp_link->link_enc->funcs->is_dig_enabled &&
-				edp_link->link_enc->funcs->is_dig_enabled(edp_link->link_enc) &&
-				dc->hwseq->funcs.edp_backlight_control &&
-				dc->hwss.power_down &&
-				dc->hwss.edp_power_control) {
-			dc->hwseq->funcs.edp_backlight_control(edp_link, false);
-			dc->hwss.power_down(dc);
-			dc->hwss.edp_power_control(edp_link, false);
-		} else {
-			for (i = 0; i < dc->link_count; i++) {
-				struct dc_link *link = dc->links[i];
-
-				if (link->link_enc->funcs->is_dig_enabled &&
-						link->link_enc->funcs->is_dig_enabled(link->link_enc) &&
-						dc->hwss.power_down) {
-					dc->hwss.power_down(dc);
-					break;
-				}
+	if (!dc->config.power_down_display_on_boot)
+		return;
+
+	edp_link = get_edp_link(dc);
+	if (edp_link &&
+			edp_link->link_enc->funcs->is_dig_enabled &&
+			edp_link->link_enc->funcs->is_dig_enabled(edp_link->link_enc) &&
+			dc->hwseq->funcs.edp_backlight_control &&
+			dc->hwss.power_down &&
+			dc->hwss.edp_power_control) {
+		dc->hwseq->funcs.edp_backlight_control(edp_link, false);
+		dc->hwss.power_down(dc);
+		dc->hwss.edp_power_control(edp_link, false);
+	} else {
+		for (i = 0; i < dc->link_count; i++) {
+			struct dc_link *link = dc->links[i];
 
+			if (link->link_enc->funcs->is_dig_enabled &&
+					link->link_enc->funcs->is_dig_enabled(link->link_enc) &&
+					dc->hwss.power_down) {
+				dc->hwss.power_down(dc);
+				break;
 			}
+
 		}
 	}
+
+	/*
+	 * Call update_clocks with empty context
+	 * to send DISPLAY_OFF
+	 * Otherwise DISPLAY_OFF may not be asserted
+	 */
+	if (dc->clk_mgr->funcs->set_low_power_state)
+		dc->clk_mgr->funcs->set_low_power_state(dc->clk_mgr);
 }
 
 void dcn10_reset_hw_ctx_wrap(

drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr.h

@@ -230,6 +230,8 @@ struct clk_mgr_funcs {
 
 	int (*get_dp_ref_clk_frequency)(struct clk_mgr *clk_mgr);
 
+	void (*set_low_power_state)(struct clk_mgr *clk_mgr);
+
 	void (*init_clocks)(struct clk_mgr *clk_mgr);
 
 	void (*enable_pme_wa) (struct clk_mgr *clk_mgr);