Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753203Ab3IKIpt (ORCPT ); Wed, 11 Sep 2013 04:45:49 -0400 Received: from mail-bn1lp0156.outbound.protection.outlook.com ([207.46.163.156]:33307 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752494Ab3IKIpr (ORCPT ); Wed, 11 Sep 2013 04:45:47 -0400 From: Matthew Garrett To: Jani Nikula CC: Aaron Lu , "Rafael J. Wysocki" , "Daniel Vetter" , ACPI Devel Mailing List , Daniel Vetter , "intel-gfx@lists.freedesktop.org" , Yves-Alexis Perez , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , Seth Forshee , "Lee, Chun-Yi" , Igor Gnatenko , Henrique de Moraes Holschuh , Lee Chun-Yi , Len Brown Subject: Re: [PATCH 2/2] ACPI / video / i915: Remove ACPI backlight if firmware expects Windows 8 Thread-Topic: [PATCH 2/2] ACPI / video / i915: Remove ACPI backlight if firmware expects Windows 8 Thread-Index: AQHOrTh4P2SImvKSpUu3tJlbFkAqyJm9JHkAgAAt1ACAADO4AIAAVGuAgAElbgCAAFwIAIAAZyGAgAB5BYCAAAAZAA== Date: Wed, 11 Sep 2013 08:45:41 +0000 Message-ID: <1378889140.945.0.camel@x230.lan> References: <522D88C3.7000808@intel.com> <5155010.Y1gov7SKhP@vostro.rjw.lan> <87eh8wail7.fsf@intel.com> <1889567.vxI8heiC3B@vostro.rjw.lan> <20130911013206.GA556@mint-spring.sh.intel.com> <87hadrycf4.fsf@intel.com> In-Reply-To: <87hadrycf4.fsf@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [2001:470:1f07:1371:91f6:fb4b:7e67:dab0] x-forefront-prvs: 09669DB681 x-forefront-antispam-report: SFV:NSPM;SFS:(377424004)(24454002)(51704005)(189002)(199002)(46102001)(19580405001)(83322001)(63696002)(77982001)(59766001)(79102001)(81816001)(51856001)(81342001)(81686001)(65816001)(36756003)(80022001)(69226001)(33646001)(74876001)(19580395003)(49866001)(47736001)(4396001)(81542001)(47976001)(76796001)(76786001)(80976001)(50986001)(54356001)(83072001)(53806001)(74366001)(76482001)(56816003)(77096001)(31966008)(56776001)(54316002)(74662001)(74706001)(74502001)(47446002)(3826001);DIR:OUT;SFP:;SCL:1;SRVR:BY2PR05MB221;H:BY2PR05MB222.namprd05.prod.outlook.com;CLIP:2001:470:1f07:1371:91f6:fb4b:7e67:dab0;RD:InfoNoRecords;MX:1;A:1;LANG:en; Content-Type: text/plain; charset="utf-8" Content-ID: <6AA43F885902D84CAE761135FBF3867B@namprd05.prod.outlook.com> MIME-Version: 1.0 X-OriginatorOrg: nebula.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id r8B8jsTG003379 Content-Length: 797 Lines: 17 On Wed, 2013-09-11 at 11:45 +0300, Jani Nikula wrote: > Before plunging forward, have you observed any difference between the > boot modes? We have reports [1] that the backlight behaviour is > different with UEFI vs. UEFI+CSM or legacy boot. So I'm wondering if the > acpi_gbl_osi_data >= ACPI_OSI_WIN_8 check in patch 2/2 is the whole > story. > > Further, if we tell the BIOS we're Windows 8 to use the tested BIOS code > paths, what guarantees do we have of UEFI+CSM or legacy boots working? We have no evidence of Windows behaving differently based on the exposed firmware type. -- Matthew Garrett ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?