From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964789AbWDDNcl (ORCPT ); Tue, 4 Apr 2006 09:32:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964808AbWDDNcl (ORCPT ); Tue, 4 Apr 2006 09:32:41 -0400 Received: from mta08-winn.ispmail.ntl.com ([81.103.221.48]:34189 "EHLO mtaout02-winn.ispmail.ntl.com") by vger.kernel.org with ESMTP id S964789AbWDDNck (ORCPT ); Tue, 4 Apr 2006 09:32:40 -0400 Message-ID: <44327574.1030803@smallworld.cx> Date: Tue, 04 Apr 2006 14:32:36 +0100 From: Ian Leonard User-Agent: Thunderbird 1.5 (X11/20051201) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Serial port problem Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, The trouble started when I upgraded a machine from FC3 to FC4. It had a serial touchscreen. With FC4 it stopped working completely. I added debug to the X input driver and found read() permanently blocked despite the file having been opened with O_NDELAY. I then tried a simple test with two machine connected with a serial cable and using minicom to send characters both ways. One was a laptop. If you typed from the failing machine to the laptop all was well. Typing the other way caused one character to be displayed and then it hung (although I could use 'cat >/dev/ttyS0' to send data just fine). I then repeated the test using 4 different motherboards. 2 exhibited the problem 2 didn't. So to recap, sending data without changing the driver settings (stty) seems to work. Configuring the port seems to cause a problem on some motherboards. One of those is a VIA mini-itx. The other is more standard Gigabyte. I have tried using the standard FC4 kernel and 2.6.15.6. Not sure what to try next, so any pointer gratefully received. -- Ian Leonard Please ignore spelling and punctuation - I did.