buffers should be since it knows about the speed.
Increase the buffer size of uvisor.
XXX The uvisor is still pitifully slow. There must be a problem somewhere.
This code probably doesn't work, because it has not been tested.
Despite several pleas for testing there doesn't seem to be any Visor owners
out there. Perhaps it will get tested if it's in -current?
Anyway, the code can at least serve as a template for how to make a USB driver
that shows up as a tty.