From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: Re: [PATCH] Default to using the native backlight control on Windows 8 systems Date: Fri, 11 Apr 2014 19:31:02 +0800 Message-ID: <5347D276.4070107@intel.com> References: <1397160803-24297-1-git-send-email-matthew.garrett@nebula.com> <534759CD.20405@intel.com> <87ppko6sjy.fsf@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com ([192.55.52.93]:11200 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754170AbaDKLaV (ORCPT ); Fri, 11 Apr 2014 07:30:21 -0400 In-Reply-To: <87ppko6sjy.fsf@intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Jani Nikula , Matthew Garrett , dri-devel@lists.freedesktop.org Cc: linux-acpi@vger.kernel.org On 04/11/2014 06:58 PM, Jani Nikula wrote: > 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 That's pretty cool :-) Regards, Aaron