From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754031Ab1AZTdJ (ORCPT ); Wed, 26 Jan 2011 14:33:09 -0500 Received: from mail-yw0-f46.google.com ([209.85.213.46]:64499 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753661Ab1AZTdH (ORCPT ); Wed, 26 Jan 2011 14:33:07 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=C8K2SE0Oc7xZS9R8j6smbv2O63+C7ATnjJtXYz4pVUl1xAvv2aGwN4n9XLG4JXxzaH flwB61Einh70LvflKZN9fo2BYbV+fx6AU14WS7AHeZsEx1+U4bgOirJP9PWoiGeh1+Os 71e/MDpMm1LPpMnoqthSR4c54eQhv49qOGE3g= Date: Wed, 26 Jan 2011 11:32:59 -0800 From: Dmitry Torokhov To: Gerd Hoffmann Cc: Mauro Carvalho Chehab , Mark Lord , Linus Torvalds , Linux Kernel , linux-input@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: 2.6.36/2.6.37: broken compatibility with userspace input-utils ? Message-ID: <20110126193259.GC29268@core.coreip.homeip.net> References: <4D3F4D11.9040302@teksavvy.com> <20110125232914.GA20130@core.coreip.homeip.net> <20110126020003.GA23085@core.coreip.homeip.net> <4D4004F9.6090200@redhat.com> <4D401CC5.4020000@redhat.com> <4D402D35.4090206@redhat.com> <20110126165132.GC29163@core.coreip.homeip.net> <4D4059E5.7050300@redhat.com> <20110126182415.GB29268@core.coreip.homeip.net> <4D4072F9.5060206@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D4072F9.5060206@redhat.com> 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 On Wed, Jan 26, 2011 at 08:16:09PM +0100, Gerd Hoffmann wrote: > Hi, > > >>>The check should be against concrete version (0x10000 in this case). > > Stepping back: what does the version mean? > Nothing, it is just a number. > 0x10000 == 1.0 ? > 0x10001 == 1.1 ? No, not really. > > Can I expect the interface stay backward compatible if only the > minor revision changes, i.e. makes it sense to accept 1.x? I am not planning on breaking backward compatibility. > > Will the major revision ever change? Does it make sense to check > the version at all? It depends. We do not have a clear way to see if new ioctls are supported (and I do not consider "try new ioctl and see if data sticks" being a good way) so that facilitated protocol version rev-up. So keymap manipulating tools might be forced to check protocol version. For the rest I think doing EVIOCGVERSION just to check that ioctl is supported is an OK way to validate that we are dealing with an event device, but that's it. BTW, maybe we should move lsinput and input-kbd into linuxconsole package, together with evtest, fftest, etc? -- Dmitry