From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757941AbZCNWl7 (ORCPT ); Sat, 14 Mar 2009 18:41:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752363AbZCNWlt (ORCPT ); Sat, 14 Mar 2009 18:41:49 -0400 Received: from minas.ics.muni.cz ([147.251.4.40]:41342 "EHLO minas.ics.muni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752137AbZCNWlt (ORCPT ); Sat, 14 Mar 2009 18:41:49 -0400 Date: Sat, 14 Mar 2009 23:41:38 +0100 From: Jan Kasprzak To: Alan Cox Cc: jirislaby@gmail.com, linux-kernel@vger.kernel.org Subject: Re: MOXA I/O errors on 2.6.28+ Message-ID: <20090314224138.GC3375@fi.muni.cz> References: <20090314213630.GA3375@fi.muni.cz> <20090314214230.352d293e@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20090314214230.352d293e@lxorguk.ukuu.org.uk> User-Agent: Mutt/1.4.2.2i X-Muni-Spam-TestIP: 147.251.48.3 X-Muni-Envelope-From: kas@fi.muni.cz X-Muni-Virus-Test: Clean X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (minas.ics.muni.cz [147.251.4.35]); Sat, 14 Mar 2009 23:41:40 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alan Cox wrote: : On Sat, 14 Mar 2009 22:36:30 +0100 : Jan Kasprzak wrote: : : > I have several servers with MOXA C320 serial boards. Starting with 2.6.28, : > some ports on MOXA boards sometimes get to a state where open("/dev/ttyMX") : > returns -EIO. I use the servers with MOXA boards as serial console hubs, : > and I think the EIO state is caused by the remote getty or the whole remote : > server being restarted. : : Sounds like a refcount bug. : : > 2.6.27 is OK, 2.6.28 and 2.6.29-rc8 is faulty. I can git bisect : > if you want (I have a spare server which I can reboot at will). : : Might be useful but let me take a look first, chances are you've provided : enough information It is this one: d450b5a0196b6442cf3f29fc611d9c8daa56b559 tty: kref usage for isicom and moxa. Reverting this commit on top of 2.6.29-rc8 (and resolving a single conflict the revert introduces in drivers/char/moxa.c) makes the problem disappear. -Yenya -- | Jan "Yenya" Kasprzak | | GPG: ID 1024/D3498839 Fingerprint 0D99A7FB206605D7 8B35FCDE05B18A5E | | http://www.fi.muni.cz/~kas/ Journal: http://www.fi.muni.cz/~kas/blog/ | >> If you find yourself arguing with Alan Cox, you’re _probably_ wrong. << >> --James Morris in "How and Why You Should Become a Kernel Hacker" <<