tree 6225f9e7e4db8dc77023887e8e70539f8b185396
parent 91cedcde1e5feede6c1e4c2086ec4f3c84c56d4f
author Jiri Slaby <jslaby@suse.cz> 1330955516 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1331235531 -0800

TTY: tty_driver, document tty->ops->shutdown limitation

Note that tty->ops->shutdown is called from whatever context the user
drops the last tty reference from. E.g. if one takes a reference in
an ISR, tty close happens on other CPU and the final tty put is from
the ISR, tty->ops->shutdown will be called from that hard irq context.

We would have a problem in vt if we start using tty refcounting from
other contexts than user there. It is because vt's shutdown uses
mutexes. This is yet to be fixed.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>