Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752548AbbK3FyO (ORCPT ); Mon, 30 Nov 2015 00:54:14 -0500 Received: from conssluserg001.nifty.com ([202.248.44.39]:35332 "EHLO conssluserg001-v.nifty.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750740AbbK3FyL (ORCPT ); Mon, 30 Nov 2015 00:54:11 -0500 X-Nifty-SrcIP: [209.85.160.182] MIME-Version: 1.0 In-Reply-To: <20151128000451.GB22297@kroah.com> References: <20151128000451.GB22297@kroah.com> Date: Mon, 30 Nov 2015 14:53:49 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: The console log is doubled if earlycon is enabled From: Masahiro Yamada To: Greg Kroah-Hartman Cc: linux-serial@vger.kernel.org, Linux Kernel Mailing List , Peter Hurley , Rob Herring Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1828 Lines: 73 2015-11-28 9:04 GMT+09:00 Greg Kroah-Hartman : > On Fri, Nov 27, 2015 at 07:21:06PM +0900, Masahiro Yamada wrote: >> Hi, >> >> >> If I add "earlycon" to the kernel parameter, the log message >> on the earlycon is also displayed to the regular console. >> In other words, the same log messages are displayed twice. >> >> I noticed this problem on v4.4-rc1. >> It has not been fixed in the mainline yet, I think. >> >> Anybody who has a clue? >> (I have not done git-bisect yet.) > > Can you do 'git bisect'? The same problem happened on v4.3. (I think I just did not notice the problem before.) So, the bad commit is not in the last merge window. I also noticed the double-log happens depending on how the console is specified. [1] Good case: both regular console and earlycon are specified via bootargs. chosen { bootargs = "console=ttyS0,115200 earlycon=uniphier,mmio32,0x54006800"; }; [2] Bad case: regular console is given by stdout-path and earlycon is specified with parameters in bootargs. chosen { bootargs = "earlycon=uniphier,mmio32,0x54006800"; stdout-path = "serial0:115200n8"; }; The early boot log is doubled. [3] Bad case: regular console is given by stdout-path and earlycon is given without parameters in bootargs chosen { bootargs = "earlycon"; stdout-path = "serial0:115200n8"; }; The early boot log is doubled. According to the experiment results, it looks like earlycon does not get along with stdout-path. -- Best Regards Masahiro Yamada -- 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/