From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Fulghum Subject: Re: serial flow control appears broken Date: Fri, 27 Jul 2007 14:05:33 -0500 Message-ID: <1185563133.23486.5.camel@x2.microgate.com> References: <46A84B4A.6070902@shaw.ca> <46A8C6F1.4080309@howardsilvan.com> <46AA2748.80703@howardsilvan.com> <46AA3801.7090204@shaw.ca> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from adsl-70-250-156-241.dsl.austtx.swbell.net ([70.250.156.241]:33839 "EHLO gw.microgate.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757418AbXG0TIN (ORCPT ); Fri, 27 Jul 2007 15:08:13 -0400 In-Reply-To: <46AA3801.7090204@shaw.ca> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Robert Hancock Cc: "Maciej W. Rozycki" , Lee Howard , linux-serial@vger.kernel.org, tytso@mit.edu, rmk@arm.linux.org.uk, linux-kernel@vger.kernel.org On Fri, 2007-07-27 at 12:22 -0600, Robert Hancock wrote: > In this situation, though, it appears it's not the TTY buffers that are > filling but the UART's own buffer. I would think this must be caused by > some kind of interrupt latency that results in not draining the FIFO in > time. You are right, this error is output when the character flag TTY_OVERRUN is encountered by n_tty.c which should be set by the driver in response to a hardware FIFO overrun (not an ldisc buffer overrun). I can't see anyplace in serial_core.c or 8250.c that sets TTY_OVERRUN. -- Paul Fulghum Microgate Systems, Ltd