drm/amd/display: reallocate MST payload when link loss

[Why]
Try to allocate MST payload but receive HPD short pulse with link loss
casue driver allocate payload twice. It cause monitor can't light up
successfully.

[How]
When driver receive HPD short pulse with link loss, we need to
deallocate payload then allocate payload.
Then we will not allocate payload twice with same sink.

Signed-off-by: Paul Hsieh <[email protected]>
Reviewed-by: Tony Cheng <[email protected]>
Acked-by: Harry Wentland <[email protected]>
Acked-by: Rodrigo Siqueira <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: Paul Hsieh

drivers/gpu/drm/amd/display/dc/core/dc_link.c

@@ -2873,6 +2873,39 @@ static enum dc_status deallocate_mst_payload(struct pipe_ctx *pipe_ctx)
 
 	return DC_OK;
 }
+
+enum dc_status dc_link_reallocate_mst_payload(struct dc_link *link)
+{
+	int i;
+	struct pipe_ctx *pipe_ctx;
+
+	// Clear all of MST payload then reallocate
+	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 &&
+				pipe_ctx->stream->dpms_off == false &&
+				pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
+			deallocate_mst_payload(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 &&
+				pipe_ctx->stream->dpms_off == false &&
+				pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
+			/* enable/disable PHY will clear connection between BE and FE
+			 * need to restore it.
+			 */
+			link->link_enc->funcs->connect_dig_be_to_fe(link->link_enc,
+									pipe_ctx->stream_res.stream_enc->id, true);
+			dc_link_allocate_mst_payload(pipe_ctx);
+		}
+	}
+
+	return DC_OK;
+}
+
 #if defined(CONFIG_DRM_AMD_DC_HDCP)
 static void update_psp_stream_config(struct pipe_ctx *pipe_ctx, bool dpms_off)
 {

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

@@ -2901,11 +2901,8 @@ bool dc_link_handle_hpd_rx_irq(struct dc_link *link, union hpd_irq_data *out_hpd
 			pipe_ctx,
 			pipe_ctx->stream->signal);
 
-		if (pipe_ctx && pipe_ctx->stream && pipe_ctx->stream->link == link &&
-				pipe_ctx->stream->dpms_off == false &&
-				pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
-			dc_link_allocate_mst_payload(pipe_ctx);
-		}
+		if (pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST)
+			dc_link_reallocate_mst_payload(link);
 
 		status = false;
 		if (out_link_loss)

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

@@ -205,6 +205,7 @@ enum dc_detect_reason {
 bool dc_link_detect(struct dc_link *dc_link, enum dc_detect_reason reason);
 bool dc_link_get_hpd_state(struct dc_link *dc_link);
 enum dc_status dc_link_allocate_mst_payload(struct pipe_ctx *pipe_ctx);
+enum dc_status dc_link_reallocate_mst_payload(struct dc_link *link);
 
 /* Notify DC about DP RX Interrupt (aka Short Pulse Interrupt).
  * Return: