From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751695Ab1AYF3L (ORCPT ); Tue, 25 Jan 2011 00:29:11 -0500 Received: from mail-yx0-f174.google.com ([209.85.213.174]:36048 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751129Ab1AYF3J (ORCPT ); Tue, 25 Jan 2011 00:29:09 -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=L440PKzIkNrWT6qpzzpWmSMYSZrdvIUR2AXbU0HBqvT4vl23ynu4fwVDM+1RItITE5 L6RGVcNCIO15a74KOEpHUT/LbgNkUYHG7KtW+u/GQLYx7pnVY1EUPih8sDQFijI3J5B/ mIPX4A5TRjtMDPkrDoTM2p8py4Ub+RE4HtSCg= Date: Mon, 24 Jan 2011 21:29:02 -0800 From: Dmitry Torokhov To: Mark Lord Cc: Linux Kernel , linux-input@vger.kernel.org Subject: Re: 2.6.36/2.6.37: broken compatibility with userspace input-utils ? Message-ID: <20110125052902.GC7850@core.coreip.homeip.net> References: <4D3C5F73.2050408@teksavvy.com> <20110124175456.GA17855@core.coreip.homeip.net> <4D3E1A08.5060303@teksavvy.com> <20110125005555.GA18338@core.coreip.homeip.net> <4D3E4DD1.60705@teksavvy.com> <20110125042016.GA7850@core.coreip.homeip.net> <4D3E5372.9010305@teksavvy.com> <20110125045559.GB7850@core.coreip.homeip.net> <4D3E59CA.6070107@teksavvy.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D3E59CA.6070107@teksavvy.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 Tue, Jan 25, 2011 at 12:04:10AM -0500, Mark Lord wrote: > On 11-01-24 11:55 PM, Dmitry Torokhov wrote: > > On Mon, Jan 24, 2011 at 11:37:06PM -0500, Mark Lord wrote: > .. > >> This results in (map->size==10) for 2.6.36+ (wrong), > >> and a much larger map->size for 2.6.35 and earlier. > >> > >> So perhaps EVIOCGKEYCODE has changed? > >> > > > > So the utility expects that all devices have flat scancode space and > > driver might have changed so it does not recognize scancode 10 as valid > > scancode anymore. > > > > The options are: > > > > 1. Convert to EVIOCGKEYCODE2 > > 2. Ignore errors from EVIOCGKEYCODE and go through all 65536 iterations. > > or 3. Revert/fix the in-kernel regression. > > The EVIOCGKEYCODE ioctl is supposed to return KEY_RESERVED for unmapped > (but value) keycodes, and only return -EINVAL when the keycode itself > is out of range. You are inventing rules. You are requesting a scancode->keycode mapping. If scancode is unknown/invalid for the device ioctl returns -EINVAL. > > That's how it worked in all kernels prior to 2.6.36, > and now it is broken. It now returns -EINVAL for any unmapped keycode, > even though keycodes higher than that still have mappings. For unmapped - yes, either KEY_RESERVED or KEY_UNKNOWN should be returned. For invalid scancodes -EINVAL shoudl be returned. Scancodes are not guaranteed to be continuous (and never have been for all devices although there are still plenty of devices with continuous scancodes, like atkbd). > > This is a bug, a regression, and breaks userspace. > I haven't identified *where* in the kernel the breakage happened, > though.. that code confuses me. :) > -- Dmitry