Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932560AbZJFNKm (ORCPT ); Tue, 6 Oct 2009 09:10:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932265AbZJFNKm (ORCPT ); Tue, 6 Oct 2009 09:10:42 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:39794 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932542AbZJFNKl (ORCPT ); Tue, 6 Oct 2009 09:10:41 -0400 Date: Tue, 6 Oct 2009 14:11:15 +0100 From: Alan Cox To: felipe.balbi@nokia.com Cc: Linux Kernel Mailing List , "dbrownell@users.sourceforge.net" Subject: Re: TTY loosing bytes ? Message-ID: <20091006141115.12ad22dd@lxorguk.ukuu.org.uk> In-Reply-To: <20091006130150.GY4452@nokia.com> References: <20091006094845.GT4452@nokia.com> <20091006114528.GV4452@nokia.com> <20091006131230.5301f711@lxorguk.ukuu.org.uk> <20091006130150.GY4452@nokia.com> X-Mailer: Claws Mail 3.7.2 (GTK+ 2.14.7; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1420 Lines: 42 > With the patch above I still get this messages but it still goes through > since not receive_buf is returning the amount of bytes actually > received. Then flush_to_ldisc() will retry those bytes on the next > iteration. Maybe this is not the desired patch though ? > > Thanks a lot for the comments Alan. First guess try the following n_tty: For some I/O patterns n_tty will lose bytes From: Alan Cox Fix the obvious disagreement between the receive path and the receive room logic. Signed-off-by: Alan Cox --- drivers/char/n_tty.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index 2e50f4d..27b28ca 100644 --- a/drivers/char/n_tty.c +++ b/drivers/char/n_tty.c @@ -95,6 +95,9 @@ static void n_tty_set_room(struct tty_struct *tty) /* tty->read_cnt is not read locked ? */ int left = N_TTY_BUF_SIZE - tty->read_cnt - 1; + if (tty->real_raw) + left = min(left, N_TTY_BUF_SIZE - tty->read_head - 1); + /* * If we are doing input canonicalization, and there are no * pending newlines, let characters through without limit, so -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/