From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933150AbcKQOd7 (ORCPT ); Thu, 17 Nov 2016 09:33:59 -0500 Received: from mx2.suse.de ([195.135.220.15]:54091 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753416AbcKQOdy (ORCPT ); Thu, 17 Nov 2016 09:33:54 -0500 Date: Thu, 17 Nov 2016 14:21:23 +0100 Message-ID: From: Takashi Iwai To: Pali =?UTF-8?B?Um9ow6Fy?= Cc: Matthew Garrett , platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, gabriele.mzt@gmail.com Subject: Re: "Setting old previous keyboard state failed" error on Dell E7270 In-Reply-To: <201611171319.22434@pali> References: <201611171319.22434@pali> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/24.5 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 17 Nov 2016 13:19:16 +0100, Pali Rohár wrote: > > On Thursday 17 November 2016 12:27:33 Takashi Iwai wrote: > > Hi, > > > > I noticed that a new machine I got yesterday, Dell Latitude E7270, > > always shows the error at boot time: > > dell_laptop: Setting old previous keyboard state failed > > > > From what I read from the code, it seems non-fatal. But is it a way > > to "fix" it? > > > > Or shouldn't we simply lower the printk level? > > > > > > thanks, > > > > Takashi > > Hi! Month ago I got private email about same problem reported by user. > Looks like that Dell changed SMBIOS interface for keyboards and have not > notified about it... User wrote that will do some research and write > info to mailing list. > > So in this case it is not non-fatal warning, but warning which telling > us: "you are doing some operation which we do not know what is doing > now...". > > Masking this warning is not a good idea. There are only two good > options: > > 1) Fix the code so it will work with that changed SMBIOS interface > > 2) Disable that code on problematic machines. > > Anyway, keyboard backlight control in kernel is implemented from program > smbios-keyboard-ctl provided and supported by Dell. I do not see any > update to that program in upstream git repository. > > http://github.com/dell/libsmbios/blob/master/src/bin/smbios-keyboard-ctl I'll give it a try shortly later. > So there are two options what could happen: > > 1) smbios-keyboard-ctl is working and kernel code not -- in this case > bug in kernel, please provide debug logs from both smbios-keyboard-ctl > and kernel and I could try to look at it > > 2) smbios-keyboard-ctl is not working too -- in this case please report > bug to that libsmbios project and Dell needs to fix it OK. thanks, Takashi