From patchwork Sun Jun 9 23:01:39 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 2695451 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by patchwork2.kernel.org (Postfix) with ESMTP id 7BF9BDF2A1 for ; Sun, 9 Jun 2013 23:53:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8F9B3E5D38 for ; Sun, 9 Jun 2013 16:53:49 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from cavan.codon.org.uk (cavan.codon.org.uk [93.93.128.6]) by gabe.freedesktop.org (Postfix) with ESMTP id EE3B0E5C1F; Sun, 9 Jun 2013 16:46:59 -0700 (PDT) Received: from x230.codon.org.uk ([2001:470:1f07:1371:6267:20ff:fec3:2318] helo=x230.lan) by cavan.codon.org.uk with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1UlocT-0005AN-L9; Mon, 10 Jun 2013 00:01:53 +0100 From: Matthew Garrett To: linux-acpi@vger.kernel.org Subject: [PATCH 3/3] i915: Don't provide ACPI backlight interface if firmware expects Windows 8 Date: Sun, 9 Jun 2013 19:01:39 -0400 Message-Id: <1370818899-8595-4-git-send-email-matthew.garrett@nebula.com> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1370818899-8595-1-git-send-email-matthew.garrett@nebula.com> References: <1370818899-8595-1-git-send-email-matthew.garrett@nebula.com> X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 2001:470:1f07:1371:6267:20ff:fec3:2318 X-SA-Exim-Mail-From: matthew.garrett@nebula.com X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false X-Mailman-Approved-At: Sun, 09 Jun 2013 16:52:49 -0700 Cc: Matthew Garrett , daniel.vetter@ffwll.ch, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, rjw@sisk.pl, seth.forshee@canonical.com, joeyli.kernel@gmail.com, lenb@kernel.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org Errors-To: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org 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 Acked-by: Daniel Vetter Tested-by: Lee, Chun-Yi --- 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))