Re: [PATCH v5 2/6] leds: triggers: Add a keyboard backlight trigger

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On Thu 2016-11-24 16:36:51, Pali Rohár wrote:
> On Thursday 24 November 2016 16:32:06 Jacek Anaszewski wrote:
> > Since it has been reported that POLLPRI notifications on brightness
> > file can lead to increased power consumption, and having my above
> > statement I don't think that it is a good idea to use brightness
> > file for this.
> 
> How is brightness file different from others that it cannot issue
> POLLPRI notification?

Reading "brightness" may or may not give you current brightness of the
led, depending on hardware limitations -- and you can't know. (It may
give you maximum brightness of trigger)

Reading "hw_current_brightness" file (if present) will give you
current brightness. In addition, it is pollable.
								Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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