Workaround for 1 fps issue

[zhsj]

reply to myself:
I changed the xorg conf to the following lines, the mouse now works fine.

```
zsj@debian ~ $ cat /etc/X11/xorg.conf.d/20-intel.conf
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "AccelMethod" "sna"
EndSection
```

Besides, I installed the xserver-xorg-video-intel on debian 9.