[LEDE-DEV] Support for KEY_BRIGHTNESS_ZERO

[Rafał Miłecki]

On 12 October 2016 at 13:16, Karl Palsson <karlp at tweak.net.au> wrote:
> Rafał Miłecki  <zajec5 at gmail.com> wrote:
>> There are some (rare) devices with a button for disabling LEDs
>> (e.g. ASUS RT-AC68U). I'm looking for a way to support such a
>> feature. Maybe at some point we could also support it as an
>> extra feature triggerable from UI.
>>
>> So basically I probably need to add some smart /etc/rc.button/
>> handler. Unfortunately I don't have a good idea for that.
>>
>> I can't relay on /etc/config/system and LEDs there as not all
>> of them are specified there. Many LEDs don't require changing
>> and they are set to default state based on platform/DT data.
>>
>> So I guess I should somehow store state of all LEDs from
>> /sys/class/leds/ and set their triggers to "none". When
>> receiving KEY_BRIGHTNESS_ZERO I should restore the state.
>>
>> Any tips for implementing this? There are various triggers with
>> various extra settings in /sys/class/leds/*/
>>
>
> Related, even with leds set in /etc/config/system, their triggers
> aren't setup until S96. How can they get setup earlier?

Well, replace 96 with a lower value? Sounds trivial to try.

> I've got
> a daemon that wants a led trigger file to be passed in for it to
> write to on activity, but the triggers aren't set. Is
> /etc/config/system ever actually useful for leds?

It is as long as you don't use some specific deamon I guess. Works for
me just fine.

-- 
Rafał