From patchwork Fri Jul 5 22:23:26 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rafael Wysocki X-Patchwork-Id: 2824391 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 692A5C0AB2 for ; Fri, 5 Jul 2013 22:14:01 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7D91220140 for ; Fri, 5 Jul 2013 22:14:00 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 9324420145 for ; Fri, 5 Jul 2013 22:13:59 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 62CD3E6034 for ; Fri, 5 Jul 2013 15:13:59 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from hydra.sisk.pl (hydra.sisk.pl [212.160.235.94]) by gabe.freedesktop.org (Postfix) with ESMTP id AC1B7E5DC6; Fri, 5 Jul 2013 15:13:46 -0700 (PDT) Received: from vostro.rjw.lan (cmk108.neoplus.adsl.tpnet.pl [83.31.138.108]) by hydra.sisk.pl (Postfix) with ESMTPSA id C7D85E3DC7; Sat, 6 Jul 2013 00:09:43 +0200 (CEST) From: "Rafael J. Wysocki" To: Matthew Garrett Subject: Re: [PATCH 3/3] i915: Don't provide ACPI backlight interface if firmware expects Windows 8 Date: Sat, 06 Jul 2013 00:23:26 +0200 Message-ID: <2962350.laXfENfrac@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.10.0+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <2888060.4Smt6Tu6bv@vostro.rjw.lan> References: <1370818899-8595-1-git-send-email-matthew.garrett@nebula.com> <2759570.WXymCRumvH@vostro.rjw.lan> <2888060.4Smt6Tu6bv@vostro.rjw.lan> MIME-Version: 1.0 Cc: linux-acpi@vger.kernel.org, daniel.vetter@ffwll.ch, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, 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: , 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 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Friday, July 05, 2013 11:40:02 PM Rafael J. Wysocki wrote: > On Friday, July 05, 2013 10:00:55 PM Rafael J. Wysocki wrote: > > On Friday, July 05, 2013 02:20:14 PM Rafael J. Wysocki wrote: > > > On Sunday, June 09, 2013 07:01:39 PM 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 > > > > --- > > > > 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)) > > > > > > > > > > Well, this causes build failures to happen when the ACPI video driver is > > > modular and the graphics driver is not. > > > > > > I'm not sure how to resolve that, so suggestions are welcome. > > > > Actually, that happened with the radeon patch. > > > > That said, ACPI_OSI_WIN_8 doesn't make much sense for !CONFIG_ACPI, for > > example. > > > > What about making acpi_video_register() do the quirk instead? We could add an > > argument to it indicating whether or not quirks should be applied. > > Actually, I wonder what about the appended patch (on top of the Aaron's > https://patchwork.kernel.org/patch/2812951/) instead of [1-3/3] from this series. Or even something as simple as this one. --- drivers/acpi/video_detect.c | 3 +++ 1 file changed, 3 insertions(+) Index: linux-pm/drivers/acpi/video_detect.c =================================================================== --- linux-pm.orig/drivers/acpi/video_detect.c +++ linux-pm/drivers/acpi/video_detect.c @@ -203,6 +203,9 @@ long acpi_video_get_capabilities(acpi_ha */ dmi_check_system(video_detect_dmi_table); + + if (acpi_gbl_osi_data >= ACPI_OSI_WIN_8) + acpi_video_support |= ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR; } else { status = acpi_bus_get_device(graphics_handle, &tmp_dev); if (ACPI_FAILURE(status)) {