Re: [PATCH] cleanup LED documentation and make it match reality

From: Pavel Machek
Date: Mon Oct 03 2016 - 05:38:57 EST


Hi!

> Thanks for the patch.
>
> On 10/03/2016 10:10 AM, Pavel Machek wrote:
> >
> >sysfs-class-led fails to mention some important details. Also fix led
> >vs LED and english.
> >
> >Signed-off-by: Pavel Machek <pavel@xxxxxx>
> >
> >--- a/Documentation/ABI/testing/sysfs-class-led
> >+++ b/Documentation/ABI/testing/sysfs-class-led
> >@@ -4,16 +4,25 @@ KernelVersion: 2.6.17
> > Contact: Richard Purdie <rpurdie@xxxxxxxxx>
> > Description:
> > Set the brightness of the LED. Most LEDs don't
> >- have hardware brightness support so will just be turned on for
> >+ have hardware brightness support, so will just be turned on for
> > non-zero brightness settings. The value is between 0 and
> > /sys/class/leds/<led>/max_brightness.
> >
> >+ Writing 0 to this file clears active trigger.
> >+
> >+ Writing non-zero to this file while trigger is active changes the
> >+ top brightness trigger is going to use.
>
> This is true only in case of timer trigger, as it uses blink_brightness
> property from struct led_classdev to cache current brightness, when the
> the LED is in the off cycle. This is part of software blink fallback
> functionality.
>
> In case of heartbeat trigger max_brightness is always used for top level
> brightness. We'd need to refactor the trigger a bit to allow for
> different top brightness levels.

Ok, do you think you could update the documenation to match the
reality? It is quite important to know what is the intended behaviour
and what are the bugs.

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

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