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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Richard Weinberger <richard@nod.at>, Jiri Slaby <jslaby@suse.cz>,
	linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org,
	Jiri Slaby <jirislaby@gmail.com>
Subject: Re: TTY: tty_port questions
Date: Sun, 25 Mar 2012 19:31:14 +0100	[thread overview]
Message-ID: <20120325183114.GM6589@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20120325155143.7ca7cb13@ultron>

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?

  parent reply	other threads:[~2012-03-25 18:31 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-10 22:26 TTY: tty_port questions Richard Weinberger
2012-03-10 22:51 ` Jiri Slaby
2012-03-10 23:21   ` Richard Weinberger
2012-03-11 11:01     ` Richard Weinberger
2012-03-12 10:26       ` Richard Weinberger
2012-03-12 10:53         ` Alan Cox
2012-03-12 11:15           ` Richard Weinberger
2012-03-12 11:48             ` Alan Cox
2012-03-24 23:20               ` Al Viro
2012-03-25 14:51                 ` Alan Cox
2012-03-25 15:14                   ` Richard Weinberger
2012-03-25 17:20                     ` Al Viro
2012-03-25 21:09                       ` Alan Cox
2012-03-25 18:31                   ` Al Viro [this message]
2012-03-25 21:06                     ` Alan Cox
2012-03-25 22:33                       ` Al Viro
2012-03-28 11:06                         ` Alan Cox

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