Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754864Ab3ITNDU (ORCPT ); Fri, 20 Sep 2013 09:03:20 -0400 Received: from smtp1-g21.free.fr ([212.27.42.1]:37516 "EHLO smtp1-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754680Ab3ITNDS (ORCPT ); Fri, 20 Sep 2013 09:03:18 -0400 Message-ID: <1379682132.9746.6.camel@oban> Subject: Re: [PATCH v2 3/3] ACPI / video: Do not register backlight if win8 and native interface exists From: Yves-Alexis Perez To: Aaron Lu Cc: linux-acpi@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Daniel Vetter , "Rafael J. Wysocki" , Matthew Garrett , Seth Forshee , Lee Chun-Yi , Richard Purdie , Igor Gnatenko , Felipe Contreras , Henrique de Moraes Holschuh , Jani Nikula Date: Fri, 20 Sep 2013 15:02:12 +0200 In-Reply-To: <1379409796-29350-4-git-send-email-aaron.lu@intel.com> References: <1379409796-29350-1-git-send-email-aaron.lu@intel.com> <1379409796-29350-4-git-send-email-aaron.lu@intel.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-tewwTmGUp+Pausd/MBrU" X-Mailer: Evolution 3.8.5-2 Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2097 Lines: 52 --=-tewwTmGUp+Pausd/MBrU Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On mar., 2013-09-17 at 17:23 +0800, Aaron Lu wrote: > According to Matthew Garrett, "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 8 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". >=20 > So for Win8 systems, if there is native backlight control interface > registered by GPU driver, ACPI video will not register its own. For > users who prefer to keep ACPI video's backlight interface, the > existing > kernel cmdline option acpi_backlight=3Dvideo can be used. >=20 > This patch is an evolution from previous work done by Matthew Garrett, > Chun-Yi Lee, Seth Forshee and Rafael J. Wysocki. >=20 > Signed-off-by: Aaron Lu Tested-by: Yves-Alexis Perez --=20 Yves-Alexis --=-tewwTmGUp+Pausd/MBrU Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) iQEcBAABCAAGBQJSPEdUAAoJEG3bU/KmdcClaAAH/3YwGtv83uQQ77PfJ1cmqADy bFH4WDtWKptZ6hCZ92ID60lPKVucJHpPWcGcDYmp/wsPtGdCUa0zWJ6Xk0XPPULI Z1RoVmyni/pXJlPK9zPRrxj2lZX857xYimgI+doISf3frUBFZFVYJIIW26QtpiQ0 WbA+ujp/46DWeGcSN88HW5alzH4pyN1nsPpEoK7KFVNLL6eV1Py3XectVPa8+TKn 15n7G9hc6YtuoJLA4NnptHxyJILXDIigluGfAFTThgBY4CFNpdD1a6F0nYma+oa+ gdP2m8GHGf95/tHwdu4c7O0OQOoyS1tITnzWuj71RO9ehGbsYZAMM1pJJJ6EfL8= =ph5b -----END PGP SIGNATURE----- --=-tewwTmGUp+Pausd/MBrU-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/