Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751199AbWHPO6F (ORCPT ); Wed, 16 Aug 2006 10:58:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751204AbWHPO6F (ORCPT ); Wed, 16 Aug 2006 10:58:05 -0400 Received: from arrakeen.ouaza.com ([212.85.152.62]:55976 "EHLO arrakeen.ouaza.com") by vger.kernel.org with ESMTP id S1751199AbWHPO6E (ORCPT ); Wed, 16 Aug 2006 10:58:04 -0400 Date: Wed, 16 Aug 2006 16:57:38 +0200 From: Raphael Hertzog To: Lennart Sorensen Cc: Linux Kernel ML Subject: Re: How to avoid serial port buffer overruns? Message-ID: <20060816145738.GA6575@ouaza.com> References: <20060816104559.GF4325@ouaza.com> <20060816143147.GC13641@csclub.uwaterloo.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20060816143147.GC13641@csclub.uwaterloo.ca> User-Agent: Mutt/1.5.12-2006-07-14 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1390 Lines: 32 On Wed, 16 Aug 2006, Lennart Sorensen wrote: > In my experience, the way to avoid overruns on a serial port was to use > a buffered serial port UART (such as a 16550A for example). I remember > my 486 wasn't reliable about 19200 or 38400 (depending on how busy the > cpu was) when using an 8250. Using a 16550A based card and I could do > 115200 without any issues since the UART had a 16 byte buffer to help > out the system. Unless your 386 has an add in card for the serial port, > it almost certainly has a very crappy UART and it would be very hard to > make it work reliably at higher speeds. I forgot to mention the kind of UART in my mail but it is a 16650A (and configured as such and detected as such) and I have overruns nevertheless. bash-2.05a# cat /proc/tty/driver/serial serinfo:1.0 driver revision: 0: uart:16550A port:000003F8 irq:4 tx:31 rx:7 RTS|CTS|DTR|DSR 1: uart:16550A port:000002F8 irq:3 tx:24 rx:7 RTS|CTS|DTR|DSR (here there's no overrun but I almost didn't use the serial port since last reboot) Cheers, -- Rapha?l Hertzog Premier livre fran?ais sur Debian GNU/Linux : http://www.ouaza.com/livre/admin-debian/ - 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/