From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:57366 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751940Ab1AYLmw (ORCPT ); Tue, 25 Jan 2011 06:42:52 -0500 Message-ID: <4D3EB734.5090100@redhat.com> Date: Tue, 25 Jan 2011 09:42:44 -0200 From: Mauro Carvalho Chehab MIME-Version: 1.0 To: Dmitry Torokhov CC: Mark Lord , 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 ? 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> <4D3E5A91.30207@teksavvy.com> <20110125053117.GD7850@core.coreip.homeip.net> In-Reply-To: <20110125053117.GD7850@core.coreip.homeip.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit List-ID: Sender: Em 25-01-2011 03:31, Dmitry Torokhov escreveu: > On Tue, Jan 25, 2011 at 12:07:29AM -0500, Mark Lord wrote: >> On 11-01-25 12:04 AM, 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. >>> >>> 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. >>> >>> 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. :) >> >> Note that this device DOES have "flat scancode space", >> and the kernel is now incorrectly signalling an error (-EINVAL) >> in response to a perfectly valid query of a VALID (and mappable) >> keycode on the remote control >> >> The code really is a valid button, it just doesn't have a default mapping >> set by the kernel (I can set a mapping for that code from userspace and it works). >> > > OK, in this case let's ping Mauro - I think he done the adjustments to > IR keymap hanlding. I lost part of the thread, but a quick search via the Internet showed that you're using the input tools to work with a Remote Controller, right? Are you using a vanilla kernel, or are you using the media_build backports? There are some distros that are using those backports also like Fedora 14. In the latter case, I found the reason why the backports were not working and I fixed it a couple days ago: http://git.linuxtv.org/media_build.git?a=commit;h=b83dc3e49d90527d8e1016d09e06f4842a6a847a The issue is simple, and it is related on how the input.c used to handle EVIOSGKEYCODE. Basically, before allowing you to change a key, it used to call EVIOCGKEYCODE to check it that key exists. However, when you're creating a new association, the key didn't exist, and, to be strict with input rules, EVIOCGKEYCODE should return -EINVAL. To circumvent that behaviour, old versions were returning 0, and associating unmapped scancodes to KEY_RESERVED. We used this workaround for a few kernel versions, while we were discussing the improvements so support larger scancodes. Yet, on all vanilla kernels, changing the keycode association works fine. However, the backport patch at media_build were not taking this workaround into account, and were just returning -EINVAL. So, the backported media drivers stopped allowing some keytable changes. The patch above fixes it. Cheers, Mauro