Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756201AbZJCNHu (ORCPT ); Sat, 3 Oct 2009 09:07:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756120AbZJCNHu (ORCPT ); Sat, 3 Oct 2009 09:07:50 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:43402 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756054AbZJCNHt (ORCPT ); Sat, 3 Oct 2009 09:07:49 -0400 Date: Sat, 3 Oct 2009 14:09:02 +0100 From: Alan Cox To: ebiederm@xmission.com (Eric W. Biederman) Cc: Johan Hovold , Greg Kroah-Hartman , Michael Trimarchi , Oliver Neukum , linux-usb@vger.kernel.org, Alan Cox , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH] USB: ftdi_sio: Remove tty->low_latency. Message-ID: <20091003140902.38628d8a@lxorguk.ukuu.org.uk> In-Reply-To: References: <20090924154023.GA27480@localhost> <200909242103.48562.oliver@neukum.org> <20090924202107.4730f2af@lxorguk.ukuu.org.uk> <20090924211459.GB27963@localhost> <4ABD020B.4040901@gandalf.sssup.it> <20090929145514.GF2152@localhost> <20090929235232.1ae6c63b@lxorguk.ukuu.org.uk> <20091002084755.GA7382@localhost> <20091002173308.6158d734@lxorguk.ukuu.org.uk> 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: 1030 Lines: 28 On Fri, 02 Oct 2009 16:00:41 -0700 ebiederm@xmission.com (Eric W. Biederman) wrote: > > > I have seen a hang in: > /bin/stty (changing the baud rate) > set_termios > tty_wait_until_sent > tty_chars_in_buffer > ftdi_chars_in_buffer > > Where the driver wedged for a serial port and no progress > was made. > > This happened to me several times with 2.6.31. My initial > hypothesis was this was a hardware error (as it only happened > on single piece of hardware). With all of the driver problems > I suspect it could be a driver bug. Driver bug I would think - or setup. If you've genuinely got the port flow controlled then a request to set the termios after the I/O will wait until a signal or carrier change (or indeed forever) quite correctly. -- 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/