Re: Vibrations in input vs. LED was Re: [PATCH v2 0/3] led: ledtrig-transient: add support for hrtimer

Pavel Machek
2017-09-20T11:15:26Z

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On Mon 2017-09-18 22:43:40, Jacek Anaszewski wrote:
> Hi,
>
> On 09/17/2017 07:50 PM, Pavel Machek wrote:
> > Hi!
> >
> >>>> Do you think such an improvement could be harmful in some way,
> >>>> even if it was made optional?
> >>>
> >>> Of course, we can make LED timing accurate down to microseconds. It will
> >>> mean increased overhead -- for "improvement" human can not perceive.
> >>>
> >>> If someone has problems with LED delays not being accurate enough... we
> >>> may want to fix it. But that is not the case here, is it?
> >>
> >> AFAIR David was mentioning that the hr_timer support is perceivable
> >
> > He said that hr_timer support is perceivable _when he is driving
> > vibration motor_. Which he should not do in the first place.
> >
> > Yes, if the difference is perceivable with LED in non-crazy
> > configuration (*), we can take the patch. Is it? Do we have someone
> > not from Google observing it?
> >
> > (*) emulating PWM using blink trigger counts as "crazy" :-)
>
> How about adding CONFIG_LED_TRIGGERS_HR_TIMER_SUPPORT, guarding the
> hr timer support in triggers (timer trigger could also benefit from it)
> with it, and adding "(EXPERIMENTAL)" tag to the config description?

Why would we want to add code in the LED subsystem that is useless for
LEDs?
Pavel
--
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