Build fixing fl2000_drm

fl2000.h

@@ -138,6 +138,6 @@ int fl2000_drm_init(struct usb_device *usb_dev);
 void fl2000_drm_cleanup(struct usb_device *usb_dev);
 /* ... and interface */
 void fl2000_drm_hotplug(struct usb_device *usb_dev);
-bool fl2000_drm_vblank(struct usb_device *usb_dev);
+void fl2000_drm_vblank(struct usb_device *usb_dev);
 
 #endif /* __FL2000_DRM_H__ */

fl2000_drm.c

@@ -93,6 +93,7 @@ struct fl2000_drm_if {
 	struct drm_device drm;
 	struct drm_simple_display_pipe pipe;
 	struct usb_device *usb_dev;
+	bool vblank_enabled;
 };
 
 DEFINE_DRM_GEM_DMA_FOPS(fl2000_drm_driver_fops);
@@ -340,6 +341,24 @@ static void fl2000_display_update(struct drm_simple_display_pipe *pipe,
 	}
 }
 
+static void fl2000_display_enable_vblank(struct drm_simple_display_pipe *pipe)
+{
+	struct drm_crtc *crtc = &pipe->crtc;
+	struct drm_device *drm = crtc->dev;
+	struct fl2000_drm_if *drm_if = container_of(drm, struct fl2000_drm_if, drm);
+
+	drm_if->vblank_enabled = true;
+}
+
+static void fl2000_display_disable_vblank(struct drm_simple_display_pipe *pipe)
+{
+	struct drm_crtc *crtc = &pipe->crtc;
+	struct drm_device *drm = crtc->dev;
+	struct fl2000_drm_if *drm_if = container_of(drm, struct fl2000_drm_if, drm);
+
+	drm_if->vblank_enabled = false;
+}
+
 /* Logical pipe management (no HW configuration here) */
 static const struct drm_simple_display_pipe_funcs fl2000_display_funcs = {
 	.mode_valid = fl2000_display_mode_valid,
@@ -420,20 +439,26 @@ void fl2000_drm_hotplug(struct usb_device *usb_dev)
 		return;
 	}
 
-	drm_kms_helper_hotplug_event(drm_if->drm);
+	drm_kms_helper_hotplug_event(&drm_if->drm);
 }
 
-bool fl2000_drm_vblank(struct usb_device *usb_dev)
+void fl2000_drm_vblank(struct usb_device *usb_dev)
 {
+	int ret;
 	struct fl2000_drm_if *drm_if;
 
 	drm_if = dev_get_drvdata(&usb_dev->dev);
 	if (!drm_if) {
 		dev_err(&usb_dev->dev, "Cannot find DRM structure!");
-		return false;
+		return;
 	}
 
-	drm_crtc_handle_vblank(drm_if->crtc);
+	if (!drm_if->vblank_enabled)
+		return;
+
+	ret = drm_crtc_handle_vblank(drm_if->crtc);
+	if (ret)
+		dev_err(&usb_dev->dev, "Cannot handle vblank event (%d)", ret);
 }
 
 static int fl2000_drm_modeset_init(struct drm_device *drm)