Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030506AbWHRQ7S (ORCPT ); Fri, 18 Aug 2006 12:59:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030502AbWHRQ7S (ORCPT ); Fri, 18 Aug 2006 12:59:18 -0400 Received: from mustang.oldcity.dca.net ([216.158.38.3]:47000 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S1030503AbWHRQ7Q (ORCPT ); Fri, 18 Aug 2006 12:59:16 -0400 Subject: Re: R: How to avoid serial port buffer overruns? From: Lee Revell To: Giampaolo Tomassoni Cc: Linux Kernel ML , Alan Cox , Russell King , Paul Fulghum In-Reply-To: References: Content-Type: text/plain Date: Fri, 18 Aug 2006 13:00:00 -0400 Message-Id: <1155920400.24907.63.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1649 Lines: 39 On Fri, 2006-08-18 at 10:48 +0200, Giampaolo Tomassoni wrote: > > On Thu, 2006-08-17 at 00:19 +0100, Russell King wrote: > > > > > > OK, thanks. FWIW here is the serial board we are using: > > > > http://www.moschip.com/html/MCS9845.html > > > > The hardware guy says "The mn9845cv, have in default 2 serial ports and > > one ISA bus, where we have connected the tl16c554, quad serial port." > > > > Hopefully Ingo's latency tracer can tell me what is holding off > > interrupts. > > I beg your pardon: I'm not used that much to interrupts handling in Linux, but this piece of code from sound/drivers/serial-u16550.c in a linux-2.6.16: OK, they are not using serial-u16550 but 8250_fourport for some reason: # cat /proc/tty/driver/serial serinfo:1.0 driver revision: 0: uart:16550A port:000003F8 irq:4 tx:0 rx:0 1: uart:unknown port:000002B8 irq:5 2: uart:unknown port:000003E8 irq:4 3: uart:unknown port:000002E8 irq:3 4: uart:16550A port:0000DD00 irq:185 tx:234335 rx:47502 RTS|DTR 5: uart:16550A port:0000E300 irq:185 tx:249926 rx:27732 RTS|DTR 6: uart:16550A port:0000E400 irq:185 tx:120958 rx:0 RTS|DTR 7: uart:16550A port:0000D000 irq:185 tx:0 rx:0 8: uart:16550A port:0000D100 irq:185 tx:0 rx:0 RTS|DTR 9: uart:16550A port:0000D200 irq:185 tx:0 rx:123406 RTS|DTR It looks like no overruns are reported, but I have to find out whether they have reproduced the bug since the last reboot. - 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/