From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753732Ab3L3DWT (ORCPT ); Sun, 29 Dec 2013 22:22:19 -0500 Received: from mail-pd0-f176.google.com ([209.85.192.176]:44702 "EHLO mail-pd0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753183Ab3L3DWS (ORCPT ); Sun, 29 Dec 2013 22:22:18 -0500 Date: Mon, 30 Dec 2013 11:21:18 +0800 From: Wang YanQing To: gregkh@linuxfoundation.org Cc: jslaby@suse.cz, airlied@redhat.com, akpm@linux-foundation.org, kilobyte@angband.pl, linux-kernel@vger.kernel.org Subject: [PATCH v2]vt: fix potential dual con_driver register for conswitchp Message-ID: <20131230032118.GB4424@udknight> Mail-Followup-To: Wang YanQing , gregkh@linuxfoundation.org, jslaby@suse.cz, airlied@redhat.com, akpm@linux-foundation.org, kilobyte@angband.pl, linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We should check whether conswitchp is registered before add it to registered_con_driver in con_init, or it will cause dual con_driver register for conswitchp. Although I haven't met it in reality, but I think it could happen for Embeded devices, who register platform con_driver earlier than call con_init. Signed-off-by: Wang YanQing --- Change v1-v2: 1: if conswitchp is registered, then make it become "system driver" by change value of first,last,flag. drivers/tty/vt/vt.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 9adb4e0..b786129 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -2876,6 +2876,12 @@ static int __init con_init(void) for (i = 0; i < MAX_NR_CON_DRIVER; i++) { struct con_driver *con_driver = ®istered_con_driver[i]; + if (con_driver->con == conswitchp) { + con_driver->flag = CON_DRIVER_FLAG_INIT; + con_driver->first = 0; + con_driver->last = MAX_NR_CONSOLES - 1; + break; + } if (con_driver->con == NULL) { con_driver->con = conswitchp; con_driver->desc = display_desc; -- 1.8.3.4.8.g69490f3.dirty