linux-kernel - Re: [PATCH v7 1/5] leds: core: add generic support for RGB LED's

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20160306205158-549-87411-mailpile@palmtree-beeroclock-net>
Date:	Sun, 06 Mar 2016 20:55:21 -0000
From:	Karl Palsson <karlp@...ak.net.au>
To:	"Heiner Kallweit" <hkallweit1@...il.com>
Cc:	"Benjamin Tissoires" <benjamin.tissoires@...hat.com>,
	"Jacek Anaszewski" <j.anaszewski@...sung.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"linux-leds@...r.kernel.org" <linux-leds@...r.kernel.org>,
	Linux USB Mailing List <linux-usb@...r.kernel.org>
Subject: Re: [PATCH v7 1/5] leds: core: add generic support for RGB LED's

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Heiner Kallweit <hkallweit1@...il.com> wrote:
> Add generic support for RGB LED's.
> 
> Basic idea is to use enum led_brightness also for the hue and
> saturation color components.This allows to implement the color
> extension w/o changes to struct led_classdev.
> 
> Select LEDS_RGB to enable building drivers using the RGB
> extension.
> 
> Flag LED_SET_HUE_SAT allows to specify that hue / saturation
> should be overridden even if the provided values are zero.
> 
> Some examples for writing values to
> /sys/class/leds/<xx>/brightness: (now also hex notation can be
> used)
> 
> 255 -> set full brightness and keep existing color if set 0 ->
> switch LED off but keep existing color so that it can be
> restored
>      if the LED is switched on again later
> 0x1000000 -> switch LED off and set also hue and saturation to
> 0 0x00ffff -> set full brightness, full saturation and set hue
> to 0 (red)
> 


I admit I hadn't seen this earlier, and I didn't spend all day
looking at previous attempts, but what's the motivation for
putting all this overloaded syntax into the "brightness" file? I
thought the point was to have a single value in each file, one of
the references I did find was
http://www.spinics.net/lists/linux-leds/msg02995.html Is there
some thread where this was decided as advantageous? Surely 0-255
for _brightness_ is what the brightness entry should do?

I'd like to set the rgb colour of a led (or hsv, that can be it's
own file too) and separately ramp the brightness up and down. I
also think it's substantially simpler and easier to use from the
user's point of view, which is surely the place you want easy
right?

Sincerely,
Karl Palsson

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
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=86mG
-----END PGP SIGNATURE-----