装的是官方的lite系统， 其他都正常，就是wifi这块一直连不上，
iwlist wlan0 scan 提示
wlan0 Failed to read scan data : Network is dow
sudo ifconfig wlan0 up 的时候 提示
SIOCSIFFLAGS: Input/output error
iwlist scan 的时候是显示有wlan0的
eth0 Interface doesn't support scanning.
lo Interface doesn't support scanning.
wlan0 Failed to read scan data : Network is down
