Comment 2 for bug 1153190

StacktraceTop:
 ?? ()
 custom_init_response (port=port@entry=0x1dd9000, response=response@entry=0x1db5b20, error=error@entry=0x1ddaf30, user_data=user_data@entry=0x1de92f0) at mm-plugin-base.c:981
 handle_response (port=<optimized out>, response=0x1dd0300, error=0x1ddaf30, callback=0x433840 <custom_init_response>, callback_data=0x1de92f0) at mm-at-serial-port.c:134
 mm_serial_port_close (self=0x1dd9000) at mm-serial-port.c:970
 supports_task_dispose (object=0x1de92f0) at mm-plugin-base.c:401