diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index 35842a6..259cb4a 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -749,10 +749,13 @@
 	intel_connector->unregister = intel_connector_unregister;
 
 	/* Pipe A maps to MIPI DSI port A, pipe B maps to MIPI DSI port C */
-	if (dev_priv->vbt.dsi.port == DVO_PORT_MIPIA)
+	if (dev_priv->vbt.dsi.port == DVO_PORT_MIPIA) {
 		intel_encoder->crtc_mask = (1 << PIPE_A);
-	else if (dev_priv->vbt.dsi.port == DVO_PORT_MIPIC)
+		intel_dsi->ports = (1 << PORT_A);
+	} else if (dev_priv->vbt.dsi.port == DVO_PORT_MIPIC) {
 		intel_encoder->crtc_mask = (1 << PIPE_B);
+		intel_dsi->ports = (1 << PORT_C);
+	}
 
 	for (i = 0; i < ARRAY_SIZE(intel_dsi_devices); i++) {
 		dsi = &intel_dsi_devices[i];
diff --git a/drivers/gpu/drm/i915/intel_dsi.h b/drivers/gpu/drm/i915/intel_dsi.h
index 97a6f62..7f5d028 100644
--- a/drivers/gpu/drm/i915/intel_dsi.h
+++ b/drivers/gpu/drm/i915/intel_dsi.h
@@ -78,6 +78,9 @@
 
 	struct intel_connector *attached_connector;
 
+	/* bit mask of ports being driven */
+	u16 ports;
+
 	/* if true, use HS mode, otherwise LP */
 	bool hs;