Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760785Ab0FQVXO (ORCPT ); Thu, 17 Jun 2010 17:23:14 -0400 Received: from lirone.symas.net ([64.71.152.235]:56145 "EHLO lirone.symas.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757638Ab0FQVXN (ORCPT ); Thu, 17 Jun 2010 17:23:13 -0400 Message-ID: <4C1A923B.4070701@symas.com> Date: Thu, 17 Jun 2010 14:23:07 -0700 From: Howard Chu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; rv:1.9.3a5pre) Gecko/20100607 Firefox 3.6 MIME-Version: 1.0 To: Alan Cox CC: linux-kernel@vger.kernel.org, Greg KH Subject: Re: [PATCH] tty: Add EXTPROC support for LINEMODE References: <20100615202924.24446d28@lxorguk.ukuu.org.uk> <4C17DA85.40803@symas.com> <4C1A7F72.6020907@symas.com> <20100617214915.3478e501@lxorguk.ukuu.org.uk> In-Reply-To: <20100617214915.3478e501@lxorguk.ukuu.org.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1586 Lines: 38 Alan Cox wrote: >>>> For Alpha this value should match OSF if possible. >> >> OSF didn't define this flag, nor did it assign that particular bit to any >> purpose. Is that good enough? > > Fine > >>> Are you suggesting that this is completely unfixable/unworkable? Would it be >>> sufficient to use kernel_termios_to_user_termios() ? > > I don't see a way to fix it sanely > >>> >> Actually using kernel_termios_to_user_termios_1(). In all supported >> architectures this structure is basically aligned with but smaller than the >> userland struct termios. > > The relationship isn't quite so simple and it may change in the future, > so this seems to be a very bad idea. Besides which syscalls are *cheap* > so simply notifying someone to reread the terminal data they care about > should be fine. In that sense it seems SVR4 got it right. OK. I'm fine with only setting a bit in the packet header, and letting the application do an ioctl/tcgetattr to discover the actual state. Next question is, should this bit still be called TIOCPKT_IOCTL (which BSD uses) or should it be called something else, since the behavior is not the same as BSD? -- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/ -- 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/