[PATCH] serial: 8250: Make ISA ports optional

[One Thousand Gnomes]

> One idea that has come up in the past but never saw an implementation
> is to make the ttyS namespace and minor numbers completely generic and
> let any serial port driver use it. This would be a major rework, but
> have the added advantage of cleaning up a number of other namespace
> issues as well. There also lots of open question, in particular how
> to maintain compatibility with existing drivers. One could imagine
> that each uart always gets a ttyS device and optionally also gets
> a device node for the same port with a driver specific chardev as
> most of them do today. Or it could be an either/or decision that is
> made at compile time or as a module parameter.

I'm not sure we should use ttyS for it. ttyS means 8250, a lot of
existing code knows what ttyS is and what sort of ioctls and the like are
assumed. A generic namespace needs not to be attached to a legacy naming 

(eg also put all serial ports in /dev/serial/0 /dev/serial/1 etc either
via the tty layer or via systemd/udev)

Alan