Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756729AbYJPSU3 (ORCPT ); Thu, 16 Oct 2008 14:20:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752726AbYJPSUV (ORCPT ); Thu, 16 Oct 2008 14:20:21 -0400 Received: from hera.kernel.org ([140.211.167.34]:57242 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752074AbYJPSUU (ORCPT ); Thu, 16 Oct 2008 14:20:20 -0400 Message-ID: <48F785B0.7000008@kernel.org> Date: Thu, 16 Oct 2008 11:19:28 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.17 (X11/20080922) MIME-Version: 1.0 To: n0ano@n0ano.com CC: Paul Bolle , donald.d.dugger@intel.com, linux-kernel@vger.kernel.org, Alan Cox Subject: Re: [PATCH] Enable console on PCI serial devices References: <200810142231.m9EMV95O002974@los-vmm.sc.intel.com> <86802c440810141539x97ceaa4meaab109fae3d9d4c@mail.gmail.com> <20081014233031.GB14490@xolotl.n0ano.com> <1224061999.25929.7.camel@test.thuisdomein> <20081015204850.GC14490@xolotl.n0ano.com> <1224153822.3587.23.camel@test.thuisdomein> <48F76A8B.6050306@kernel.org> <20081016171218.GD14490@xolotl.n0ano.com> In-Reply-To: <20081016171218.GD14490@xolotl.n0ano.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1773 Lines: 46 n0ano@n0ano.com wrote: > On Thu, Oct 16, 2008 at 09:23:39AM -0700, Yinghai Lu wrote: >> ... >> earlycon= and conole= share uart[8250]... >> >> the difference console= will start from early console and switch normal console automatically if the ttyS come out with same io/mmio address etc. >> > > But there is no advantage to `earlycon' given that you can accomplish > the same thing with `console'. The only use that I can see is if > you specify `earlycon' without specifying `console' and then all > you get are the initial kernel messages, after the serial drivers > intializes all further messages go to the VGA. If makes much more > sense to me to just use the `console' parameter to get all kernel > messages on the serial port, and then there is no need for > `earlycon'. > /* Check for early params. */ static int __init do_early_param(char *param, char *val) { struct obs_kernel_param *p; for (p = __setup_start; p < __setup_end; p++) { if ((p->early && strcmp(param, p->str) == 0) || (strcmp(param, "console") == 0 && strcmp(p->str, "earlycon") == 0) ) { if (p->setup_func(val) != 0) printk(KERN_WARNING "Malformed early option '%s'\n", param); } } /* We accept everything at this stage. */ return 0; } we need that holder in console sections to compare with console and earlycon. YH -- 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/