Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755219Ab3GYIIR (ORCPT ); Thu, 25 Jul 2013 04:08:17 -0400 Received: from mga11.intel.com ([192.55.52.93]:51692 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755093Ab3GYIIA (ORCPT ); Thu, 25 Jul 2013 04:08:00 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,742,1367996400"; d="scan'208";a="375754984" From: Jani Nikula To: "Rafael J. Wysocki" , Linus Torvalds Cc: Aaron Lu , Matthew Garrett , * =?utf-8?Q?SAM=C3=8D?= * , intel-gfx , LKML , ACPI Devel Maling List , Igor Gnatenko Subject: Re: [Intel-gfx] Linux 3.11-rc2 [backlight] [ASUS N56VZ] In-Reply-To: <6051153.b6TE1dlrel@vostro.rjw.lan> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20130724210200.GY5939@phenom.ffwll.local> <6051153.b6TE1dlrel@vostro.rjw.lan> User-Agent: Notmuch/0.15.2+227~g0ff681e (http://notmuchmail.org) Emacs/23.3.1 (x86_64-pc-linux-gnu) Date: Thu, 25 Jul 2013 11:09:27 +0300 Message-ID: <87hafjxdqg.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1914 Lines: 49 On Thu, 25 Jul 2013, "Rafael J. Wysocki" wrote: > On Wednesday, July 24, 2013 02:05:15 PM Linus Torvalds wrote: >> On Wed, Jul 24, 2013 at 2:02 PM, Daniel Vetter wrote: >> > >> > I think a i915 module option should be doable, otoh people seem to have a >> > viable workaround by setting a different acpi os version already. >> >> At least the original claim was that if you set a non-windows8 acpi os >> version, you hit other bugs.. >> >> But yeah, if we just do a plain revert, that may be the only option >> for the people for whom the current (to-be-reverted) patches made >> things work. > > Well, I wonder what about the appended (untested) patch? Rafael, before going there, I've been trying to wrap my (poor, rusty after vacation) head around commit 8c5bd7adb2ce47e6aa39d17b2375f69b0c0aa255 Author: Rafael J. Wysocki Date: Thu Jul 18 02:08:06 2013 +0200 ACPI / video / i915: No ACPI backlight if firmware expects Windows 8 and I can't see how it could work. First, the ACPI_VIDEO_SKIP_BACKLIGHT flag seems to be checked before it's actually set anywhere. Buried deep in the calls from acpi_video_bus_add(), acpi_video_verify_backlight_support() is used before acpi_video_backlight_quirks() gets called. (Perhaps if i915 is reloaded, this goes right as the flags are already set.) Second, with i915 that has opregion support, __acpi_video_register() should only ever get called once. Which means the acpi_walk_namespace() with video_unregister_backlight() should never get called in register. Please enlighten me. BR, Jani. -- Jani Nikula, Intel Open Source Technology Center -- 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/