Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751182AbWHPOfs (ORCPT ); Wed, 16 Aug 2006 10:35:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751183AbWHPOfs (ORCPT ); Wed, 16 Aug 2006 10:35:48 -0400 Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:887 "EHLO pd4mo3so.prod.shaw.ca") by vger.kernel.org with ESMTP id S1751182AbWHPOfs (ORCPT ); Wed, 16 Aug 2006 10:35:48 -0400 Date: Wed, 16 Aug 2006 08:35:05 -0600 From: Robert Hancock Subject: Re: How to avoid serial port buffer overruns? In-reply-to: To: Raphael Hertzog Cc: Linux Kernel ML Message-id: <44E32D19.3090405@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-15; format=flowed Content-transfer-encoding: 7bit References: User-Agent: Thunderbird 1.5.0.5 (Windows/20060719) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1015 Lines: 26 Raphael Hertzog wrote: > (Please CC me when replying) > > Hello, > > While using Linux on low-end (semi-embedded) hardware (386 SX 40Mhz, 8Mb > RAM), I discovered that Linux on that machine would suffer from serial > port buffer overruns quite easily if I use a baudrate high enough (I start > loosing bytes at >19200 bauds and I would like to make it reliable up to > 115 kbauds). I check if overruns are happening with > /proc/tty/driver/serial ("oe" field). What kind of serial port are you using? If it's an unbuffered 8250-type port, it will NEVER be reliable at higher baud rates. You want a 16550 (or better) port. -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/ - 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/