From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756466AbbJUWzE (ORCPT ); Wed, 21 Oct 2015 18:55:04 -0400 Received: from mout.kundenserver.de ([212.227.17.13]:54814 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755305AbbJUWzB (ORCPT ); Wed, 21 Oct 2015 18:55:01 -0400 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: Peter Hurley , Masahiro Yamada , Linux Kernel Mailing List , Stefan Agner , linux-serial@vger.kernel.org Subject: Re: console vs earlycon ? Date: Thu, 22 Oct 2015 00:54:28 +0200 Message-ID: <4134303.BAT7dSJRN3@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <5627E679.1050207@hurleysoftware.com> References: <3890353.0icCv0Zeuq@wuerfel> <5627E679.1050207@hurleysoftware.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:ne1qCXUTo2m091OUfyZiWW+UF5Ce0MVfeeBoQ0aog+NyNqIgroP 8C0MwBzMRBlJkDTDvGpvz5JbZssD2tRmJ4LEBb3fGpTIcg/ePs5HhSLTGZJbGqSmzWjRSMq loJ3qeEaGZQGR9cdr+wekU8Q9HrDJMVMQk/RXXuhWGTdIm8EXgzy8eGh2ILyOQd3dJm668o gAsC9xzhx+v+Y0CXzJgXA== X-UI-Out-Filterresults: notjunk:1;V01:K0:ZAJ2H4KDrVo=:FRh81LJKjULUJfcEX17x3n WRmk0VooDUlP/76AxBtnTf/nrjUJtKlp7Xe2wiK2hdc3zZ0Ai2j3K0FsgPi26FOiYaYOsVfnw uyrLJvmIRHAcqb3PMG+aelrcQtyQSePRIq4A8ixGeleiYcumf4Lgi256eX7JM4z8089UiCpZW hvmMilqZj7gb5qfiPzdDbSirezCGwKpmQiBqW485lLI2dEsY3sXI8CncVuWw+y+nMBuQR5gzm qXTPBcaICCsz+vtNYsvjRD27SJdrjWHKbucSqRvtIvbHZ3cA59jNvP4y8FAUUJ8gsBMcukFSI SWBUe+wnpBTPiNg4CL6qE1BErkn0eZ1//2geszZSS954bxzdsypwcpk6EvULUaTq7XnXDyyqA 3asETVcIZ1u6bJkKNdZxZeilYfbfzTd8ZtU8mmYTyEbH3zirCDjs4RbmkINMeXN6QIQ5kMZvD BU/9nyfPukPgrram6sqejESNNiCE6phunsHHZoY/U7QIEV8UZuHCN73F4DHP0+RCPh0HSOEVM ttKV+ZJcZbM0cy/M7/Fy14px3wIeK57RJJ7A0Lwwx8iRLHo1Ctqtyn0Ko/hFnGcnUaZQzOHd9 qoS9WwTI1FrsHDnnHOOtsblRw/aAfi7vxRc3qsiddF1xr1Ki+Q0Z1fdkdFrDCDDp/J9/6xLaN gF4hjIx+lLzA25lwWX3LRi2j90GEchplESqdMCKj6gfRuk+g2Ctf7JfehyGr6ts64WrYCNkFW 1B+gTAg6zM9cf0Is Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 21 October 2015 15:24:41 Peter Hurley wrote: > On 10/21/2015 03:00 PM, Arnd Bergmann wrote: > > Yes, I see this as a tradeoff: we want the console to be as early as > > possible in order to report boot-time errors to the user, but not so early > > to require hacks that can cause problems themselves. earlycon has to > > do some scary stuff and is relatively recent, while the hacks > > necessary for console_init() are much older and better tested. > > I assume you mean the hacks necessary to get _earlycon_ working at > console_init() time, because the hacks necessary to get non-8250 > serial consoles working at console_init() would be extensive and > brand new. > No, I was just being slow and assumed that the 51 drivers that come with a console_initcall() do something in there to actually start the console, but you are right that most of them don't actually do that. They just call register_console() and wait for the device to show up later. Arnd