Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750902AbWBCO25 (ORCPT ); Fri, 3 Feb 2006 09:28:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750904AbWBCO25 (ORCPT ); Fri, 3 Feb 2006 09:28:57 -0500 Received: from clix.aarnet.edu.au ([192.94.63.10]:40343 "EHLO clix.aarnet.edu.au") by vger.kernel.org with ESMTP id S1750902AbWBCO24 (ORCPT ); Fri, 3 Feb 2006 09:28:56 -0500 Message-ID: <43E36850.5030900@aarnet.edu.au> Date: Sat, 04 Feb 2006 00:57:28 +1030 From: Glen Turner Organization: Australia's Academic & Research Network User-Agent: Mozilla Thunderbird 1.0.7-1.1.fc4 (X11/20050929) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Russell King CC: Alan Cox , linux-kernel@vger.kernel.org Subject: Re: 8250 serial console fixes -- issue References: <1138844838.5557.17.camel@localhost.localdomain> <43E2B8D6.1070707@aarnet.edu.au> <20060203094042.GB30738@flint.arm.linux.org.uk> In-Reply-To: <20060203094042.GB30738@flint.arm.linux.org.uk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-MDSA: Yes X-Spam-Score: -104.901 BAYES_00,USER_IN_WHITELIST Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2393 Lines: 71 Hi Russell, Thanks for your response. > A normal user can't produce arbitarily formatted > kernel messages They don't need to provide an entire message, just a AT string (a vector which a user could control could be a volume label on removable media). > You'd rather we threw away these messages? When option 'r' is set, yes. Because Data Carrier Detect is not asserted there can't be anything that is going to read the messages. All we are doing is taking a long time to drop each character off the end of the serial cable. Since the kernel takes a very long time to boot with the 'r' option and no attached console the current situation isn't correct. There's one very nasty practical effect. Hayes modems hang up if any character is typed during the interval between off-hook and Data Carrier Detect (ie, the negotiation period where the speaker outputs the tones). If you're continually writing console messages (say from a failing disk) then you can't successfully dial in to read the messages to find out why the machine is hosed. > It'd help if you talked to the right person - I've been looking after > the serial layer since 2.5.something. See my e-mail to you of 2003-10-21, which started: Hi Russell, I have ported the patch which fixes all kernel bugs reported to me as the maintainer of the "Remote Serial Console HOWTO" from 2.4 to Linus's BitKeeper (2.6.0-test8). and contained the patch at The previous patch of 2002-10-13 gave a much longer description of the bugs and fixes: [PATCH] 0/3 Fix serial console flow control [PATCH] 1/3 Fix serial console flow control, serial.c As I said earlier I'm happy to once more forward-port the patch, test it and present it using the current version control system as long as the effort is worth doing. Regards, Glen -- Glen Turner Tel: (08) 8303 3936 or +61 8 8303 3936 Australia's Academic & Research Network www.aarnet.edu.au - 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/