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Date: Wed, 28 Feb 2007 15:37:02 +0000
From: Alan <alan@lxorguk.ukuu.org.uk>
To: Christopher Meller <cmeller@innominate.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Question on tty line discipline
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On Wed, 28 Feb 2007 14:47:12 +0100
Christopher Meller <cmeller@innominate.com> wrote:

> Hi,
> 
> I have a question concerning the line discipline behaviour for serial
> devices.
> When the line discipline is set via ioctl from  user space to e.g. N_PPP and the userspace program returns without resetting  the line discipline back to N_TTY, the serial device cannot be used (ENODV) until an appropriate  ioctl (to N_TTY) is performed. Is there any reason for the fact that the line discipline is not reset by the kernel , when closing the device. 

No special reason, it has simply always been that way. Getty and friends
are expected to put the tty back into a sane state.