Messages in this thread | | | Subject | Re: [PATCH ] leds: add new transient trigger for one shot timer support | From | Shuah Khan <> | Date | Mon, 23 Apr 2012 16:22:25 -0600 |
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On Mon, 2012-04-23 at 15:45 +1000, NeilBrown wrote: > On Mon, 23 Apr 2012 07:29:59 +0200 Jonas Bonn <jonas@southpole.se> wrote: > > > > > On Mon, 2012-04-23 at 11:56 +1000, NeilBrown wrote: > > > I wonder if we should allow control of the brightness during the "on" time as > > > well. > > > You could set the brightness after enabling the timer, but awkward pauses or > > > races could then leave the "led" permanently on. > > > > echo transient > trigger > > echo 200 > duration > > echo 1 > activate > context switch - lots of IO - time passes, 200ms or more, led gets turned of > and then back to: > > echo 100 > brightness > > led gets turned on and there is nothing to turn it off. > > Not a likely case I agree, but not impossible. > > The problem is that just setting the brightness will turn the led on > independent of the start of the trigger (unless you set the brightness to 0 - > that disables the trigger). > Neil/Jonas,
Thanks for a good discussion and ideas. Are you okay with supporting the following use-case as a first cut implementation and see how that works and then add brightness adjustment later?
echo transient > trigger echo 200 > duration echo 1 > activate
I am taking a look at "safe_delay_show" and "safe_delay_store" in drivers/md/md.c. I think I can easily change what I have now to do what these routines do. i.e going with seconds as units based on Neil's suggestion.
I did make the change to name the properties duration and activate, dropping the transient pre-fix on both properties.
Thanks, -- Shuah
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