Linux on a Getac B300 Tip to fix it turning its self back on.

 I love rugged laptops and I have a couple of Getac B300's for ham radio and DIY drone stuff that are rain resistant and sunlight readable.... you know for outdoorsy stuff.  But there is a massively annoying thing they do when running Linux.   They turn themselves back on after having  linux do a shutdown.   

I found out why,  the Intel chipset they use have a hardware issue.  DH77 based motherboards flip out on power off if the USB ports are set to xHCI on shutdown.    Windows by default switches all usb poarts to EHCI so this is why it doesnt happen with windows.

to fix it,  go into /etc/default/grub. and add xhci_hcd.quirks=270366 into the GRUB_CMDLINE_LINUX_DEFAULT variable.

Then issue a sudo update-grub.   reboot.  then shut down to test.

It will make your shutdown a LOT slower,  I had to wait an extra 200ms on shutdown with that setting.   I used that time for meditation and writing my autobiography.

Note this will work on a lot of other laptops and montherboards infected with the Intel H77 express chipset.