From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Norris Subject: Re: [PATCH] Documentation: Add entry for dell-laptop sysfs interface Date: Tue, 30 Dec 2014 21:31:49 -0800 Message-ID: <20141231053149.GA3764@norris-Latitude-E6410> References: <1417628493-29323-1-git-send-email-gabriele.mzt@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1417628493-29323-1-git-send-email-gabriele.mzt@gmail.com> Sender: platform-driver-x86-owner@vger.kernel.org To: Gabriele Mazzotta Cc: dvhart@infradead.org, 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 List-Id: linux-api@vger.kernel.org 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. >=20 > Signed-off-by: Gabriele Mazzotta > Signed-off-by: Pali Roh=E1r > --- > .../ABI/testing/sysfs-platform-dell-laptop | 60 ++++++++++++= ++++++++++ > 1 file changed, 60 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-platform-dell-lap= top >=20 > diff --git a/Documentation/ABI/testing/sysfs-platform-dell-laptop b/D= ocumentation/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 Roh=E1r > +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 fro= m 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 o= r 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. NB: I came across this because (1) I'd really like to be able to turn the keyboard backlight on, th= e timeout off, and the ALS off; and (2) I noticed there was a new driver patch in 3.19 (nice! thanks!), where previously there must have been some kind of half-functional working driver -- I could get backlight control, but it always timed out too quickly. It seems like /sys/.../als_setting is documented to handle the latter part of (1), but its implementation does not match. Thanks, Brian P.S. The author of this page [1] might be interested in these new drive= r additions. [1] http://www.cs.bham.ac.uk/~axs/laptop/dell-e6410-fn-keys.html