From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756247Ab2BGD53 (ORCPT ); Mon, 6 Feb 2012 22:57:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:8367 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755828Ab2BGD52 (ORCPT ); Mon, 6 Feb 2012 22:57:28 -0500 Message-ID: <4F30A120.2050208@redhat.com> Date: Mon, 06 Feb 2012 22:57:20 -0500 From: Adam Jackson User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:9.0) Gecko/20111222 Thunderbird/9.0.1 MIME-Version: 1.0 To: Greg KH CC: linux-kernel@vger.kernel.org, arnd@arndb.de Subject: Re: [PATCH] char/mem: Make /dev/port less obviously broken (v0) References: <1328569322-19165-1-git-send-email-ajax@redhat.com> <20120207001558.GA30840@kroah.com> In-Reply-To: <20120207001558.GA30840@kroah.com> 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 On 2/6/12 7:15 PM, Greg KH wrote: > Who would use this new ioctl? And if it's been working ok until now, > why is it needed? I'll go out on a limb and say nobody's been seriously using /dev/port. libpciaccess would like to, since it avoids needing iopl, and also avoids duplicating all the kernel's per-arch logic for port access in userspace. But if it's not going to give me the cycle size I asked for I need to fix it before I can use it. Otherwise you get what I'm getting, which is a vesa driver that doesn't work. Adding the ioctl was just me being polite and assuming that user-kernel ABI was a thing we actually believe in. If it's not, great, let's just fix /dev/port to not be idiotic. If it is, I'd prefer not wasting the memory on another inode. > If you want something "new" like this, why not just create /dev/ioport > or something like that to always use the proper alignment and not need > an ioctl at all? If you really want that shed painted a different color, fine. - ajax