From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jani Nikula Subject: Re: [PATCH] Default to using the native backlight control on Windows 8 systems Date: Fri, 11 Apr 2014 13:58:57 +0300 Message-ID: <87ppko6sjy.fsf@intel.com> References: <1397160803-24297-1-git-send-email-matthew.garrett@nebula.com> <534759CD.20405@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mga09.intel.com ([134.134.136.24]:58585 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753559AbaDKK6M (ORCPT ); Fri, 11 Apr 2014 06:58:12 -0400 In-Reply-To: <534759CD.20405@intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Aaron Lu , Matthew Garrett , dri-devel@lists.freedesktop.org Cc: linux-acpi@vger.kernel.org On Fri, 11 Apr 2014, Aaron Lu wrote: > On 04/11/2014 04:13 AM, Matthew Garrett wrote: >> The list of machines in the "Use native backlight" table is getting longer >> and longer, which is a solid indication that we're doing something wrong. >> Disable the ACPI backlight interface if the system claims to be Windows 8 >> or later. > > And has a native backlight control interface. This. One thing we were doing wrong in i915 was unconditionally registering a native backlight interface even when it was not functional. We can't really know whether that is the case except by trusting the VBT, and although we've been let down in the past, trusting the VBT on this one is probably a better approximation of the reality than assuming it always works. Thus we've queued [1] and [2] for 3.15 which should help. [1] http://cgit.freedesktop.org/drm-intel/commit/?id=39fbc9c8f6765959b55e0b127dd5c57df5a47d67 [2] http://cgit.freedesktop.org/drm-intel/commit/?id=c675949ec58ca50d5a3ae3c757892f1560f6e896 >> Let's at least get this into -next for 3.16 and figure out whether the >> drivers actually work now. > > I agree. Agreed. BR, Jani. -- Jani Nikula, Intel Open Source Technology Center