drm/amd/display: Power down hw blocks on boot

[WHY]
On headless boot a DIG may be turned on by VBIOS on RN.  This leads to
display_count being non-zero in hybrid graphics cases leading to SMU
DISPLAY_OFF message not being sent.

[HOW]
Power down hardware on boot
if seamless boot is not occurring
(power_down_display_on_boot == 1)
Signed-off-by: Sung Lee <sung.lee@amd.com>
Reviewed-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1361,6 +1361,35 @@ void dcn10_init_hw(struct dc *dc)
 					!dc->res_pool->hubbub->ctx->dc->debug.disable_stutter);
 	}
 
+	/* In headless boot cases, DIG may be turned
+	 * on which causes HW/SW discrepancies.
+	 * To avoid this, power down hardware on boot
+	 * if DIG is turned on and seamless boot not enabled
+	 */
+	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->hwss.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;
+				}
+
+			}
+		}
+	}
+
 	for (i = 0; i < res_pool->audio_count; i++) {
 		struct audio *audio = res_pool->audios[i];
 

drivers/gpu/drm/amd/display/dc/dcn21/dcn21_init.c

@@ -90,6 +90,7 @@ static const struct hw_sequencer_funcs dcn21_funcs = {
 	.set_cursor_sdr_white_level = dcn10_set_cursor_sdr_white_level,
 	.optimize_pwr_state = dcn21_optimize_pwr_state,
 	.exit_optimized_pwr_state = dcn21_exit_optimized_pwr_state,
+	.power_down = dce110_power_down,
 };
 
 static const struct hwseq_private_funcs dcn21_private_funcs = {

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

@@ -75,9 +75,13 @@ struct hw_sequencer_funcs {
 	void (*wait_for_mpcc_disconnect)(struct dc *dc,
 			struct resource_pool *res_pool,
 			struct pipe_ctx *pipe_ctx);
+	void (*edp_backlight_control)(
+			struct dc_link *link,
+			bool enable);
 	void (*program_triplebuffer)(const struct dc *dc,
 		struct pipe_ctx *pipe_ctx, bool enableTripleBuffer);
 	void (*update_pending_status)(struct pipe_ctx *pipe_ctx);
+	void (*power_down)(struct dc *dc);
 
 	/* Pipe Lock Related */
 	void (*pipe_control_lock)(struct dc *dc,