From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751973AbbABEZs (ORCPT ); Thu, 1 Jan 2015 23:25:48 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:48688 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751533AbbABEZq (ORCPT ); Thu, 1 Jan 2015 23:25:46 -0500 Date: Thu, 1 Jan 2015 20:25:26 -0800 From: Darren Hart To: Gabriele Mazzotta Cc: Brian Norris , mjg59@srcf.ucam.org, linux-api@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, libsmbios-devel@lists.us.dell.com, Srinivas_G_Gowda@dell.com, Michael_E_Brown@dell.com, pali.rohar@gmail.com, A.Sloman@cs.bham.ac.uk Subject: Re: [PATCH] Documentation: Add entry for dell-laptop sysfs interface Message-ID: <20150102042525.GC51121@vmdeb7> References: <1417628493-29323-1-git-send-email-gabriele.mzt@gmail.com> <20141231053149.GA3764@norris-Latitude-E6410> <1636595.UbTko9mUNA@xps13> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1636595.UbTko9mUNA@xps13> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 31, 2014 at 12:20:59PM +0100, Gabriele Mazzotta wrote: > On Tuesday 30 December 2014 21:31:49 Brian Norris wrote: > > Hi, > > > > On Wed, Dec 03, 2014 at 06:41:33PM +0100, Gabriele Mazzotta wrote: > > > Add the documentation for the new sysfs interface of dell-laptop > > > that allows to configure the keyboard illumination on Dell systems. > > > > > > Signed-off-by: Gabriele Mazzotta > > > Signed-off-by: Pali Rohár > > > --- > > > .../ABI/testing/sysfs-platform-dell-laptop | 60 ++++++++++++++++++++++ > > > 1 file changed, 60 insertions(+) > > > create mode 100644 Documentation/ABI/testing/sysfs-platform-dell-laptop > > > > > > diff --git a/Documentation/ABI/testing/sysfs-platform-dell-laptop b/Documentation/ABI/testing/sysfs-platform-dell-laptop > > > new file mode 100644 > > > index 0000000..7969443 > > > --- /dev/null > > > +++ b/Documentation/ABI/testing/sysfs-platform-dell-laptop > > > @@ -0,0 +1,60 @@ > > > +What: /sys/class/leds/dell::kbd_backlight/als_setting > > > +Date: December 2014 > > > +KernelVersion: 3.19 > > > +Contact: Gabriele Mazzotta , > > > + Pali Rohár > > > +Description: > > > + This file allows to control the automatic keyboard > > > + illumination mode on some systems that have an ambient > > > + light sensor. Write 1 to this file to enable the auto > > > + mode, 0 to disable it. > > [...] > > > > This entry appears wrong, or at least incomplete. My system boots with a > > default value of 18, and the 'set' implementation accepts any value from > > 0 to 255. > > > > According to the comments in dell-laptop.c, the value actually means > > something different than on/off: > > > > cbArg3, byte0 Desired setting of ALS value that turns the light on or off. > > > > Admittedly, I'm not clear on what the intended interface is, as I've > > never had the ALS / keyboard backlight controls all working properly on > > my laptop in the first place, but I thought this would be the right > > place to ask about getting the documentation and driver in sync. > > Hi, > > You are perfectly right, the documentation is wrong and I'm sorry for > that. als_setting should allow you to define when the keyboard > backlight has to be turned on or off depending on the value reported > by the ambient light sensor. > > Please note that not everything that is in libsmbios [1] is implemented > in the kernel driver. Take a look at it, recently there have been few > changes related to the ALS settings. Probably they are not needed given > that you are able to set the threshold with the current kernel driver, > but you might find something interesting. > > I'll submit a patch to correct the documentation, thanks for reporting. Thanks Gabriele, let's make sure to get this into this rc cycle, sooner the better. Thanks, -- Darren Hart Intel Open Source Technology Center