From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751096AbWDJRGD (ORCPT ); Mon, 10 Apr 2006 13:06:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751223AbWDJRGD (ORCPT ); Mon, 10 Apr 2006 13:06:03 -0400 Received: from mail.gmx.net ([213.165.64.20]:47837 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S1751096AbWDJRGC (ORCPT ); Mon, 10 Apr 2006 13:06:02 -0400 X-Authenticated: #13409387 Message-ID: <443A8D70.3040906@gmx.net> Date: Mon, 10 Apr 2006 18:53:04 +0200 From: Gunther Mayer User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20050920 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Steven Rostedt CC: LKML Subject: Re: [PATCH -rt] Buggy uart (for 2.6.16) References: <1144676225.12145.30.camel@localhost.localdomain> In-Reply-To: <1144676225.12145.30.camel@localhost.localdomain> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Steven Rostedt wrote: >Ingo, > >I've noticed that you dropped my "buggy uart" patch. Probably because >the 2.6.14 version would cause a deadlock on 2.6.16. I've sent you a >new update, but it must have been lost in all the noise. Here's the >patch again. If you don't think this is a bug, try running the attached >program on the machine that deadlocked (it is the one with the buggy >uart). Without the patch, the serial_test will miss a wake up, and then >be stuck in the sleeping TASK_INTERRUPTIBLE state (at least you can >still kill it). With the patch, it runs fine. > >I ran the program with the following parameters: > ># ./serial_test /dev/ttyS0 115200 8 0 0 4 > >(Disclaimer: I did not write this serial_test. It was hacked up by my >customer to show me that this bug exists). > >This may also be a bug with the vanilla kernel, since I don't see why it >is not. I'll run more tests on the vanilla kernel, and if it too misses >a wake up, I'll submit this to vanilla as well. > > >Some 8250 uarts don't zero out the NO_INTERRUPT bit of the IIR register > > Can you name the exact 8250 model which is buggy ?