[SeaBIOS] USB/xHCI device detection issues

[Matt DeVillier]

Greetings,

my Haswell ChromeBox users are still reporting intermittent issues with USB device detection at boot on SeaBIOS 1.81, with both the stock/google firmware and my coreboot builds (the ChromeBox only has xHCI ports).  The most common problem is that the USB device fails to be listed in the boot menu; far less common is the device being listed but failing to boot.

Finally got one of them to provide a cbmem log, which I had done at level 7.  Looks like the device (a Sandisk Cruser flash drive) reported 'medium not present', which to me doesn't make sense for a flash drive.  

Would appreciate any insight, the log is at http://pastebin.com/Ujj0WRwA

cheers,
Matt