drm/amd/display: blank dp stream before re-train the link

[Why]
When link loss happened, monitor can not light up if only re-train the
link.

[How]
Blank all the DP streams on this link before re-train the link, and then
unblank the stream

Signed-off-by: Xiaodong Yan <Xiaodong.Yan@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@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/core/dc_link_dp.c

@@ -2899,6 +2899,12 @@ bool dc_link_handle_hpd_rx_irq(struct dc_link *link, union hpd_irq_data *out_hpd
 					sizeof(hpd_irq_dpcd_data),
 					"Status: ");
 
+		for (i = 0; i < MAX_PIPES; i++) {
+			pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
+			if (pipe_ctx && pipe_ctx->stream && pipe_ctx->stream->link == link)
+				link->dc->hwss.blank_stream(pipe_ctx);
+		}
+
 		for (i = 0; i < MAX_PIPES; i++) {
 			pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
 			if (pipe_ctx && pipe_ctx->stream && pipe_ctx->stream->link == link)
@@ -2918,6 +2924,12 @@ bool dc_link_handle_hpd_rx_irq(struct dc_link *link, union hpd_irq_data *out_hpd
 		if (pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST)
 			dc_link_reallocate_mst_payload(link);
 
+		for (i = 0; i < MAX_PIPES; i++) {
+			pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
+			if (pipe_ctx && pipe_ctx->stream && pipe_ctx->stream->link == link)
+				link->dc->hwss.unblank_stream(pipe_ctx, &previous_link_settings);
+		}
+
 		status = false;
 		if (out_link_loss)
 			*out_link_loss = true;