diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index cb5367c..5cdc2f4 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1557,18 +1557,109 @@ static void intel_ddi_destroy(struct drm_encoder *encoder)
 	intel_dp_encoder_destroy(encoder);
 }
 
+static bool intel_ddi_set_personality(struct intel_encoder *encoder,
+				      struct intel_crtc_config *pipe_config)
+{
+	struct drm_device *dev = encoder->base.dev;
+	struct intel_connector *connector;
+	int connectors = 0;
+	enum port port = intel_ddi_get_encoder_port(encoder);
+
+	list_for_each_entry(connector, &dev->mode_config.connector_list,
+			    base.head) {
+
+		if (connector->new_encoder != encoder)
+			continue;
+
+		connectors++;
+		if (WARN_ON(connectors > 1))
+			return false;
+
+		switch (connector->base.connector_type) {
+		case DRM_MODE_CONNECTOR_HDMIA:
+		case DRM_MODE_CONNECTOR_HDMIB:
+			pipe_config->ddi_personality = INTEL_OUTPUT_HDMI;
+			break;
+		case DRM_MODE_CONNECTOR_DisplayPort:
+			pipe_config->ddi_personality = INTEL_OUTPUT_DISPLAYPORT;
+			break;
+		case DRM_MODE_CONNECTOR_eDP:
+			pipe_config->ddi_personality = INTEL_OUTPUT_EDP;
+			break;
+		default:
+			WARN(1, "DRM connector type %d\n",
+			     connector->base.connector_type);
+			return false;
+		}
+
+		if (encoder->type == pipe_config->ddi_personality)
+			continue;
+
+		/* We expect eDP to always have encoder->type correctly set, so
+		 * it shouldn't reach this point. */
+		if (pipe_config->ddi_personality == INTEL_OUTPUT_EDP) {
+			DRM_ERROR("DDI %c, type %s marked as eDP\n",
+				   port_name(port),
+				   intel_output_name(encoder->type));
+			return false;
+		}
+
+		/*
+		 * We can't change the DDI type if we already have a connected
+		 * device on this port. The first time a DDI is used though
+		 * (encoder_type is INTEL_OUTPUT_UNKNOWN) and we force a
+		 * connector to be connected (either trought the kernel command
+		 * line or KMS) we need to comply.
+		 */
+		 if (encoder->type != INTEL_OUTPUT_UNKNOWN &&
+		     connector->base.status == connector_status_connected) {
+			 DRM_DEBUG_KMS("Can't set DDI %c personality to %s, it has a connected %s device\n",
+			 		port_name(port),
+					intel_output_name(encoder->type),
+					intel_output_name(pipe_config->ddi_personality));
+			 return false;
+		}
+
+		DRM_DEBUG_KMS("Setting DDI %c personality to %s\n",
+			      port_name(port),
+			      intel_output_name(pipe_config->ddi_personality));
+	}
+
+	return true;
+
+}
+
+void intel_ddi_commit_personality(struct intel_crtc *crtc)
+{
+	struct intel_encoder *encoder = intel_ddi_get_crtc_encoder(&crtc->base);
+
+	switch (encoder->type) {
+	case INTEL_OUTPUT_HDMI:
+	case INTEL_OUTPUT_DISPLAYPORT:
+	case INTEL_OUTPUT_EDP:
+	case INTEL_OUTPUT_UNKNOWN:
+		encoder->type = crtc->config.ddi_personality;
+		break;
+	case INTEL_OUTPUT_ANALOG:
+		break;
+	default:
+		WARN(1, "Output type %s\n", intel_output_name(encoder->type));
+		break;
+	}
+}
+
 static bool intel_ddi_compute_config(struct intel_encoder *encoder,
 				     struct intel_crtc_config *pipe_config)
 {
-	int type = encoder->type;
 	int port = intel_ddi_get_encoder_port(encoder);
 
-	WARN(type == INTEL_OUTPUT_UNKNOWN, "compute_config() on unknown output!\n");
+	if (!intel_ddi_set_personality(encoder, pipe_config))
+		return false;
 
 	if (port == PORT_A)
 		pipe_config->cpu_transcoder = TRANSCODER_EDP;
 
-	if (type == INTEL_OUTPUT_HDMI)
+	if (pipe_config->ddi_personality == INTEL_OUTPUT_HDMI)
 		return intel_hdmi_compute_config(encoder, pipe_config);
 	else
 		return intel_dp_compute_config(encoder, pipe_config);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index b5dbc88..16750c4 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7810,6 +7810,8 @@ static int haswell_crtc_mode_set(struct intel_crtc *crtc,
 				 int x, int y,
 				 struct drm_framebuffer *fb)
 {
+	intel_ddi_commit_personality(crtc);
+
 	if (!intel_ddi_pll_select(crtc))
 		return -EINVAL;
 
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 5ab813c..bf3267c 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -386,6 +386,9 @@ struct intel_crtc_config {
 
 	bool dp_encoder_is_mst;
 	int pbn;
+
+	/* This should be INTEL_OUTPUT_*. */
+	int ddi_personality;
 };
 
 struct intel_pipe_wm {
@@ -817,6 +820,7 @@ void intel_ddi_init_dp_buf_reg(struct intel_encoder *encoder);
 void intel_ddi_clock_get(struct intel_encoder *encoder,
 			 struct intel_crtc_config *pipe_config);
 void intel_ddi_set_vc_payload_alloc(struct drm_crtc *crtc, bool state);
+void intel_ddi_commit_personality(struct intel_crtc *crtc);
 
 /* intel_frontbuffer.c */
 void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
