From: Jiri Slaby <jslaby@suse.cz>
Date: Mon, 5 Mar 2012 13:51:56 +0000 (+0100)
Subject: TTY: tty_driver, document tty->ops->shutdown limitation
X-Git-Tag: v3.4-rc1~185^2~83
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=26b23209c0ea5503824df60b8f218fb04b80cad0;p=pandora-kernel.git

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>
---

Reading git-diff-tree failed