From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752631AbYAVMjl (ORCPT ); Tue, 22 Jan 2008 07:39:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758023AbYAVMj3 (ORCPT ); Tue, 22 Jan 2008 07:39:29 -0500 Received: from out3.smtp.messagingengine.com ([66.111.4.27]:54001 "EHLO out3.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751929AbYAVMj2 (ORCPT ); Tue, 22 Jan 2008 07:39:28 -0500 X-Sasl-enc: 7FRH5w3+76DLVK33mN6GACQ2en8z2W4TXUM8oPHYBDcA 1201005566 Date: Tue, 22 Jan 2008 10:39:23 -0200 From: Henrique de Moraes Holschuh To: Matthew Garrett Cc: Zhang Rui , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, len.brown@intel.com Subject: Re: [PATCH] Rationalise ACPI backlight implementation Message-ID: <20080122123923.GC15490@khazad-dum.debian.net> References: <20071226020325.GA21099@srcf.ucam.org> <1200990809.7424.31.camel@acpi-sony.sh.intel.com> <20080122114605.GA23983@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080122114605.GA23983@srcf.ucam.org> X-GPG-Fingerprint: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 22 Jan 2008, Matthew Garrett wrote: > On Tue, Jan 22, 2008 at 04:33:29PM +0800, Zhang Rui wrote: > > I have no obvious objection on either of these two proposals. > > But one thing to mention is that > > both of these two patches is written on the assumption that the > > brightness levels listed in _BCL method are in ascending order, while > > this is not stated in the ACPI spec. > > Is this a problem? > > The driver already makes that assumption, and it's implicit in the spec. Actually, no, it is not implicit. The spec clearly states that the brightness values will be cycled through the ones given by that list. It is implicit that brightness up actions will cycle through the list in order, and brightness down will cycle through the list in reverse order. If a vendor where to decide to place the most used brightness values in the beginning of the list, and the rest of it later, he would be allowed to do so. Nobody was weird enough to do it yet though, AFAIK. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh