From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH 3/3] i915: Don't provide ACPI backlight interface if firmware expects Windows 8 Date: Mon, 10 Jun 2013 09:40:31 +0200 Message-ID: <20130610074031.GG22870@phenom.ffwll.local> References: <1370818899-8595-1-git-send-email-matthew.garrett@nebula.com> <1370818899-8595-4-git-send-email-matthew.garrett@nebula.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-ea0-f181.google.com ([209.85.215.181]:53912 "EHLO mail-ea0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090Ab3FJHkh (ORCPT ); Mon, 10 Jun 2013 03:40:37 -0400 Received: by mail-ea0-f181.google.com with SMTP id a15so2764684eae.40 for ; Mon, 10 Jun 2013 00:40:36 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1370818899-8595-4-git-send-email-matthew.garrett@nebula.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Matthew Garrett Cc: linux-acpi@vger.kernel.org, seth.forshee@canonical.com, joeyli.kernel@gmail.com, daniel.vetter@ffwll.ch, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, lenb@kernel.org, rjw@sisk.pl On Sun, Jun 09, 2013 at 07:01:39PM -0400, Matthew Garrett wrote: > Windows 8 leaves backlight control up to individual graphics drivers rather > than making ACPI calls itself. There's plenty of evidence to suggest that > the Intel driver for Windows doesn't use the ACPI interface, including the > fact that it's broken on a bunch of machines when the OS claims to support > Windows 8. The simplest thing to do appears to be to disable the ACPI > backlight interface on these systems. > > Signed-off-by: Matthew Garrett Make sense and I guess it's easier to merge this all through the acpi tree. So Acked-by: Daniel Vetter > --- > drivers/gpu/drm/i915/i915_dma.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c > index 3b315ba..23b6292 100644 > --- a/drivers/gpu/drm/i915/i915_dma.c > +++ b/drivers/gpu/drm/i915/i915_dma.c > @@ -1661,6 +1661,9 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags) > /* Must be done after probing outputs */ > intel_opregion_init(dev); > acpi_video_register(); > + /* Don't use ACPI backlight functions on Windows 8 platforms */ > + if (acpi_osi_version() >= ACPI_OSI_WIN_8) > + acpi_video_backlight_unregister(); > } > > if (IS_GEN5(dev)) > -- > 1.8.2.1 > -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch