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Message-ID: <4A80702D.20701@gmail.com>
Date: Mon, 10 Aug 2009 21:08:29 +0200
From: Artur Skawina <art.08.09@gmail.com>
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To: Linus Torvalds <torvalds@linux-foundation.org>
CC: Ray Lee <ray-lk@madrabbit.org>, Alan Cox <alan@lxorguk.ukuu.org.uk>,
       "Rafael J. Wysocki" <rjw@sisk.pl>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: xterm loses data (pty regression)
References: <4A803CE7.20201@gmail.com> <2c0942db0908101007t54c39b64k2800b2c320969318@mail.gmail.com> <alpine.LFD.2.01.0908101016100.3288@localhost.localdomain> <alpine.LFD.2.01.0908101105040.3602@localhost.localdomain>
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Linus Torvalds wrote:
> 
>> (Do ^S/^Q, see data loss)

> I think it's really this trivial.
> 
> That pty commit removed the checking for tty->stopped in 
> pty_write_buffer() for no clear reason. And when it did that, it broke all 
> the pausing logic in drivers/char/n_tty.c.
> 
> Can you confirm?

>  static int pty_write_room(struct tty_struct *tty)
>  {
> +	if (tty->stopped)
> +		return 0;
>  	return pty_space(tty->link);
>  }

w/ this, the pty writes now block again after ^Q, and the data loss is gone.

Thanks,

artur