minor fixes

lv_porting/lv_port_disp_templ.c

@@ -96,6 +96,9 @@ void lv_port_disp_init(void)
     /*Used to copy the buffer's content to the display*/
     disp_drv.flush_cb = disp_flush;
 
+    /*Set a display buffer*/
+    disp_drv.buffer = &disp_buf_2;
+
 #if USE_LV_GPU
     /*Optionally add functions to access the GPU. (Only in buffered mode, LV_VDB_SIZE != 0)*/