From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Clifton Subject: Re: BIOS update breaks HP2125nr backlight keys Date: Fri, 17 Aug 2007 12:44:44 +0100 Message-ID: <1187351084.22480.4.camel@localhost> References: <46C4DF04.6020306@ou.edu> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from ppsw-8.csi.cam.ac.uk ([131.111.8.138]:54752 "EHLO ppsw-8.csi.cam.ac.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750897AbXHQMNv (ORCPT ); Fri, 17 Aug 2007 08:13:51 -0400 Received: from dsl-217-155-45-158.zen.co.uk ([217.155.45.158]:49590 helo=[192.168.2.8]) by ppsw-8.csi.cam.ac.uk (smtp.hermes.cam.ac.uk [131.111.8.158]:465) with esmtpsa (LOGIN:pcjc2) (SSLv3:DHE-RSA-AES256-SHA:256) id 1IM0Fo-00087i-Rf (Exim 4.67) for linux-acpi@vger.kernel.org (return-path ); Fri, 17 Aug 2007 12:44:36 +0100 In-Reply-To: <46C4DF04.6020306@ou.edu> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-acpi@vger.kernel.org On Thu, 2007-08-16 at 18:34 -0500, Ryan May wrote: > Hi, > > I recently updated the BIOS on my HP Pavilion dv2125nr laptop to F.34 > (to enable the virtualization instructions). Since I did this, the Fn > keys to control brightness have failed to work properly under Linux, > though they work fine before booting (ie. at Grub). Hitting the Fn keys > caused the brightness to change to the minimum possible. In fact, > /proc/acpi/video/VGA/LCD/brightness would show that the level was set to > 0 (though 20 was the lowest available). I was still able to control the > brightness manually via /proc interface however. > > My investigations seem to indicate that HP, in their wisdom, seem to > have removed the _BQC method from their BIOS code. It seems that the > ACPI code in Linux that handles the key events to change the brightness > use the _BQC method without checking for success, which explains why the > level being set was garbage. However, the /proc interface for > brightness seems to only use device->brightness->curr to get the current > level. Do you happen to see a _BCQ method in the DSDT instead? My HP nc6320 has that, and last time I looked, it seemed like it could plausibly be a Microsoft induced rename / typo, as this method is mentioned for getting brightness on a Windows Vista compatible box. Did the bios update also mention any fixes for Vista compatibility? -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!)