From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265998AbUBPXrD (ORCPT ); Mon, 16 Feb 2004 18:47:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265999AbUBPXrD (ORCPT ); Mon, 16 Feb 2004 18:47:03 -0500 Received: from atlrel8.hp.com ([156.153.255.206]:54739 "EHLO atlrel8.hp.com") by vger.kernel.org with ESMTP id S265998AbUBPXpY (ORCPT ); Mon, 16 Feb 2004 18:45:24 -0500 From: Bjorn Helgaas To: Keith Owens Subject: Re: 2.6.3-rc3 serial console woes Date: Mon, 16 Feb 2004 16:45:14 -0700 User-Agent: KMail/1.5.4 Cc: linux-kernel@vger.kernel.org, Russell King References: <2719.1076973910@kao2.melbourne.sgi.com> In-Reply-To: <2719.1076973910@kao2.melbourne.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200402161645.14151.bjorn.helgaas@hp.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Monday 16 February 2004 4:25 pm, Keith Owens wrote: > Spoke too soon. That one line patch makes the serial console available > early in boot. But as soon as /sbin/init runs, the console is > gibberish due to a speed mismatch. Completely reverting > > http://linux.bkbits.net:8080/linux-2.5/cset@1.1653?nav=index.html|ChangeSet@-7d > > works fine. Since this is a -rc kernel, can we revert the cset until > it is fixed? Reverting for now sounds like the right thing to me. I would like to understand what's going on, though. For the serial console to work early, serial8250_console_setup() must be returning zero. So we can't be taking this return: if (!port->ops) return -ENODEV; and therefore, the hunk in serial_core.c shouldn't have any effect either. So is it merely the fact that we call serial8250_late_console_init()? I wouldn't expect that to make any difference, because the setup() call from serial8250_console_init() should have succeeded, so CON_ENABLED should have been set, and we don't do anything in that case. Keith, can you tell me how to reproduce this? Bjorn