From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [REGRESSION/PATCH] acpi: blacklist win8 OSI for ASUS Zenbok Prime UX31A Date: Wed, 31 Jul 2013 15:00:10 +0100 Message-ID: <20130731140010.GA24560@srcf.ucam.org> References: <1375125658-1223-1-git-send-email-felipe.contreras@gmail.com> <3453253.oZLO1ChPbL@vostro.rjw.lan> <37178266.QXgbv9rq0i@vostro.rjw.lan> <20130731051421.GA15766@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([93.93.128.6]:38135 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752686Ab3GaOAP (ORCPT ); Wed, 31 Jul 2013 10:00:15 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Felipe Contreras Cc: "Rafael J. Wysocki" , Aaron Lu , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Len Brown , Linus Torvalds On Wed, Jul 31, 2013 at 06:32:47AM -0500, Felipe Contreras wrote: > On Wed, Jul 31, 2013 at 12:14 AM, Matthew Garrett wrote: > > There's no mechanism for an OS to know whether or not a firmware > > implementation will actually turn the backlight off at 0, so there's no > > way the OS can define the lowest backlight state as anything other than > > "May or may not turn the screen off". > > Yes there is; quirks. We aren't going to maintain a quirk list in order to support a guarantee that was never made. "0" as a backlight level has potentially meant "screen off" since the interface was first introduced. -- Matthew Garrett | mjg59@srcf.ucam.org