From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D548C433F5 for ; Fri, 11 Feb 2022 14:17:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347113AbiBKORq (ORCPT ); Fri, 11 Feb 2022 09:17:46 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:55332 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229781AbiBKORo (ORCPT ); Fri, 11 Feb 2022 09:17:44 -0500 X-Greylist: delayed 369 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Fri, 11 Feb 2022 06:17:42 PST Received: from mail.enpas.org (zhong.enpas.org [IPv6:2a03:4000:2:537::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D4CEE188 for ; Fri, 11 Feb 2022 06:17:42 -0800 (PST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by mail.enpas.org (Postfix) with ESMTPSA id DAFD8FF837; Fri, 11 Feb 2022 14:11:31 +0000 (UTC) From: Max Staudt To: Greg Kroah-Hartman , Jiri Slaby Cc: linux-kernel@vger.kernel.org, Max Staudt Subject: [PATCH] tty: Reserve ldisc 29 for development purposes Date: Fri, 11 Feb 2022 15:10:36 +0100 Message-Id: <20220211141036.6403-1-max@enpas.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It's handy to have an ldisc number free for out-of-tree testing. This way, a new ldisc can be developed on any running system, without having to recompile the kernel just to define a new number. This is the highest number (and also the last one) available under the old numbering scheme, so let's reserve it before it's too late. >From now on, every new ldisc upstreamed will have to increment NR_LDISCS in lockstep with its addition to the table in tty.h. Signed-off-by: Max Staudt --- include/uapi/linux/tty.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/tty.h b/include/uapi/linux/tty.h index a58deb3061eb..9d0f06bfbac3 100644 --- a/include/uapi/linux/tty.h +++ b/include/uapi/linux/tty.h @@ -6,8 +6,6 @@ * 'tty.h' defines some structures used by tty_io.c and some defines. */ -#define NR_LDISCS 30 - /* line disciplines */ #define N_TTY 0 #define N_SLIP 1 @@ -39,5 +37,9 @@ #define N_SPEAKUP 26 /* Speakup communication with synths */ #define N_NULL 27 /* Null ldisc used for error handling */ #define N_MCTP 28 /* MCTP-over-serial */ +#define N_DEVELOPMENT 29 /* Manual out-of-tree testing */ + +/* Always the newest line discipline + 1 */ +#define NR_LDISCS 30 #endif /* _UAPI_LINUX_TTY_H */ -- 2.30.2