Re: TTY: tty_port questions

Al Viro
2012-03-25T18:31:22Z

How is tty_port supposed to work wrt hotplug? I.e. are those guys (OK,
the structures they are embedded into) supposed to live as long as
tty_driver lives? AFAICS, for serial we have an extra layer atop of
those guys (uart_port) and that's where removals seem to act, but there
seems to be more to it...

Suppose we handle uml reconfig requests as port removal + port addition;
what's needed to make sure that port is out of use and we can play with
it without stepping on anyone's toes? Something along the lines of what
uart_remove_one_port() is doing? I.e. tty_unregister_device() + tty_vhangup()?
But serial_core seems to be open-coding tty_port_open() for some reason
and _there_ we have port->count updates under port->mutex, so the
situation might be different...

Is there any FMtoR/thread/search terms that would give the description of
the situation?