From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754483AbYI0RbV (ORCPT ); Sat, 27 Sep 2008 13:31:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752999AbYI0RbK (ORCPT ); Sat, 27 Sep 2008 13:31:10 -0400 Received: from mail.daysofwonder.com ([87.98.213.69]:34381 "EHLO mail.daysofwonder.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752980AbYI0RbJ (ORCPT ); Sat, 27 Sep 2008 13:31:09 -0400 X-Greylist: delayed 616 seconds by postgrey-1.27 at vger.kernel.org; Sat, 27 Sep 2008 13:31:08 EDT Message-ID: <48DE6B6E.4050306@daysofwonder.com> Date: Sat, 27 Sep 2008 19:20:46 +0200 From: Brice Figureau User-Agent: Thunderbird 2.0.0.17 (Macintosh/20080914) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Serial console not working after device detection. Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On two of my servers (some Dell poweredge 1850 and 2850), booting a 2.6.26 debian kernel while at the same time looking at the serial console, nothing is printed after the following snippet: ... Linux agpgart interface v0.103 Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a NS16550A ???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? The serial port of these servers is configured as 115200n8 and connected to an Opengear serial console server for remote administration through ssh. This is not an issue per-se, but for an unknown reason 2.6.25 and 2.6.26 debian kernels don't boot succesfully, and I'm trying to understand why, which is a complex task when you don't see anything :-) The latest known debian kernel that boots fine is a 2.6.22 (I didn't try 2.6.23 or 2.6.24). On this kernel that boots, the first lines that the serial console displays are those from the initrd. After the boot the dmesg contains the following lines which are just after the last line displayed (ie the serial8250: ttyS0 is at... line): pnp: the driver 'serial' has been registered pnp: match found with the PnP device '00:06' and the driver 'serial' 00:06: ttyS0 at I/O 0x3f8 (irq = 4) is a NS16550A pnp: the driver 'parport_pc' has been registered FDC 0 is a National Semiconductor PC87306 RAMDISK driver initialized: 16 RAM disks of 65536K size 1024 blocksize ... Is there anything I can do to display something after the device detection, in order to understand why those kernels are not booting? Many thanks for any answer, Please CC: me on replies, as I'm not subscribed to the list. -- Brice Figureau