Messages in this thread | | | Subject | Re: [PATCH ] leds: add new transient trigger for one shot timer support | From | Shuah Khan <> | Date | Sun, 22 Apr 2012 17:51:27 -0600 |
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Hi Jonas,
activate does sound better and having units in the property name is a good idea. Will make the changes including the 0200 change for activate. Will change the transient_time to transient_time_msec (no problem using duration, just that time is shorter :)
> A couple of questions: > > i) Why is it important for you to maintain the LED state? One use-case that would be easier for user to comprehend would be to have a constant timer that runs periodically. time value doesn't change and by simply writing 1 or 0, timer with a value specified by the time file can be started. The following use-case is a good example for what I am talking about:
echo transient > trigger echo n > transient_time repeat the following step as needed: echo 1 > transient_enabled - start timer = transient_time to run once echo 1 > transient_enabled - start timer = transient_time to run once echo none > trigger
This could be accomplished by simply using just the time property, however, each time, the same timer value needs to be echoed. Not a big deal, however time value either needs to stay where it is even when a timer is not running, or clear it 0. I don't like clearing the time value. Here is why. The use-case is very similar to a stop and start timer function on a watch for example. I typically set a time value and then activate and deactivate as needed without needing to reset the time value.
> > ii) Why do you need to be able to cancel the timer? Here is an example where canceling timer is necessary. Phone is in silent mode and a call comes in. When call comes in phone will start vibrating (maybe vibrate mode set for 2 seconds), when caller answers, vibrate mode needs to deactivated right away by stopping the vibrate mode and canceling the timer. > > As I understand this trigger (and your use-case), this is about being > able to turn on a LED (signal) and forget about it, knowing that it will > be extinguished in due time without any intervention. So I would leave > it at that; don't even present an option to intervene. > > That said, there is already a way to intervene: I can always write 0 to > 'brightness' to extinguish the led immediately.
That is correct. brightness could be used, however having a distinct name-space might be better for future changes instead of overloading brightness.
Hope this helps explain my reasoning to keep transient state.
Thanks, -- Shuah
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