drm/amd/display: Add control flag to dc_stream_state to skip eDP BL off/link off

Add control flag to dc_stream_state to skip eDP BL off/link off.
Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Max Tseng <max.tseng@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@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_stream.h

@@ -302,6 +302,7 @@ struct dc_stream_state {
 	bool vblank_synchronized;
 	bool fpo_in_use;
 	struct mall_stream_config mall_stream_config;
+	bool skip_edp_power_down;
 };
 
 #define ABM_LEVEL_IMMEDIATE_DISABLE 255

drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c

@@ -1216,6 +1216,7 @@ void dce110_blank_stream(struct pipe_ctx *pipe_ctx)
 	struct dce_hwseq *hws = link->dc->hwseq;
 
 	if (link->local_sink && link->local_sink->sink_signal == SIGNAL_TYPE_EDP) {
+		if (!stream->skip_edp_power_down)
 			hws->funcs.edp_backlight_control(link, false);
 		link->dc->hwss.set_abm_immediate_disable(pipe_ctx);
 	}

drivers/gpu/drm/amd/display/dc/link/link_dpms.c

@@ -2207,9 +2207,8 @@ static enum dc_status enable_link(
 	 * link settings. Need to call disable first before enabling at
 	 * new link settings.
 	 */
-	if (link->link_status.link_active) {
+	if (link->link_status.link_active && !stream->skip_edp_power_down)
 		disable_link(link, &pipe_ctx->link_res, pipe_ctx->stream->signal);
-	}
 
 	switch (pipe_ctx->stream->signal) {
 	case SIGNAL_TYPE_DISPLAY_PORT:
@@ -2327,8 +2326,10 @@ void link_set_dpms_off(struct pipe_ctx *pipe_ctx)
 		dc->hwss.disable_stream(pipe_ctx);
 	} else {
 		dc->hwss.disable_stream(pipe_ctx);
+		if (!pipe_ctx->stream->skip_edp_power_down) {
 			disable_link(pipe_ctx->stream->link, &pipe_ctx->link_res, pipe_ctx->stream->signal);
 		}
+	}
 
 	if (pipe_ctx->stream->timing.flags.DSC) {
 		if (dc_is_dp_signal(pipe_ctx->stream->signal))