Alan - the only issue that remains is handling the invalid baud rate
situation - if left to individual drivers to do this, we will see them
doing stuff (as was the case with this very patch - and was the case
prior to serial_core) such as using dev_err() to print an error and
merely returning from their set_termios function, or clamping to some
speed and not feeding back to userspace what they're actually doing.

They've had years to adapt. It's time they got with the program or just
broke horribly.

Alan