From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763937AbcALR4N (ORCPT ); Tue, 12 Jan 2016 12:56:13 -0500 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:45618 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763919AbcALR4I (ORCPT ); Tue, 12 Jan 2016 12:56:08 -0500 Message-Id: <1452621367.403228.490087522.151796A7@webmail.messagingengine.com> X-Sasl-Enc: vSwgiWaUylBkhf0kGdg6HmAojtelODEYQMRq23DPfYWP 1452621367 From: Henrique de Moraes Holschuh To: Johannes Stezenbach Cc: =?ISO-8859-1?Q?Pali=20Roh=E1r?= , Darren Hart , Pavel Machek , ibm-acpi-devel@lists.sourceforge.net, platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, "Fabio D'Urso" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain X-Mailer: MessagingEngine.com Webmail Interface - ajax-6cda141f Subject: Re: [PATCH] thinkpad_acpi: Add support for keyboard backlight Date: Tue, 12 Jan 2016 15:56:07 -0200 In-Reply-To: <20160112163514.GA24900@sig21.net> References: <1450982818-11694-1-git-send-email-pali.rohar@gmail.com> <20160111190411.GE10643@malice.jf.intel.com> <1452540480.2848000.489039714.26068C20@webmail.messagingengine.com> <201601112103.01145@pali> <20160111211228.GA4171@sig21.net> <1452614830.376787.489968026.5FAEDB86@webmail.messagingengine.com> <20160112163514.GA24900@sig21.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 12, 2016, at 14:35, Johannes Stezenbach wrote: > On Tue, Jan 12, 2016 at 02:07:10PM -0200, Henrique de Moraes Holschuh > wrote: > > Is the ACPI AML for fn+space readable enough, or is it trapping directly > > into SMM? Because if it interacts with the traditional higher-level > > ACPI AML we already use to talk to the thinklight (and now to the > > backlight), it should be relatively easy to fix the driver to better > > support the x230. > > I have no clue about ACPI, do you have some hints > how to get the info you want? I found this: > > sudo acpidump > acpidata.dat > acpixtract -sSSDT acpidata.dat > acpixtract -sDSDT acpidata.dat > iasl -d DSDT.dat SSDT*.dat > > ..and then look at the .dsl files that contain the AML assembler. > > But what to look out for? Well, you should familiarize yourself with ACPI AML a bit. Then, look for the ACPI methods that thinkpad-acpi (and the patch to add backlight support) calls, and try to work out how they work in your thinkpad. Typical thinkpad firmware behavior is to sometimes have a lower level implementation, a higher level ACPI API that the O.S. is supposed to call (and which will call into the lower level implementation, or to the work itself). We want to stick to the higher level API, as it is more stable. Use of lower-level APIs or direct EC access must be whitelist-restricted. > PS: failed to mention my x230 kernel was still 4.2.x in case it matters It doesn't. -- "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