From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: Bug in tty cooked mode kernel 3.12.3 Date: Sat, 7 Dec 2013 23:18:11 -0800 Message-ID: <20131208071811.GA12028@kroah.com> References: <20131107184607.eklhad@comcast.net> <20131208053621.GA6445@kroah.com> <20131108011609.eklhad@comcast.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41375 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751047Ab3LHHQl (ORCPT ); Sun, 8 Dec 2013 02:16:41 -0500 Content-Disposition: inline In-Reply-To: <20131108011609.eklhad@comcast.net> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Karl Dahlke Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org On Sun, Dec 08, 2013 at 01:16:09AM -0500, Karl Dahlke wrote: > As per your direction, I applied Peters patch to n_tty.c, > which looked like it was in the ballpark, echoing newline etc, > but it did not fix the problem. > It is still reproducible on my system as below. > > > Come up in run level 3, command line mode, > > and bring up two consoles with bash in cooked mode. > > Set a simple prompt like this. > > > > PS1='$ ' > > > > Switch to console 2 via alt-f2. > > Hit return. > > The cursor should drop to a new line then give you the $ prompt. > > But it puts the $ prompt next too the old one, then drops down > > to a blank line. > > The $ prompt and the crlf are out of sequence. > > Hit return a few more times and it will straighten itself out. > > Then switch back to console 1 alt-f1 > > Hit return and the same bug, > > $ $ > > > > hit return a few more times to straighten it out. > > Switch back to console 2 and the same problem. > > Thank you for your quick reply,and the patch to try. > I'm afraid however this is still an unsolved problem. > Realize that it pops up rarely and randomly in just about any cooked program; > I chose the console switch example because it most reliably reproduces the bug. Ah, sorry, wrong patch series. Search lkml for: Subject: [PATCH tty-next 0/4] tty: Fix ^C echo for a 4 patch series that should resolve this issue. If you could test that out, and let us know, that would be great. thanks, greg k-h