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

[Jacek Anaszewski]

On 10/03/2016 11:38 AM, Pavel Machek wrote:
> 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.

Applied the patch (removed extra empty line) after improving heartbeat
trigger [0] to support brightness levels other then max_brightness.

[0] 
https://git.kernel.org/cgit/linux/kernel/git/j.anaszewski/linux-leds.git/commit/?h=for-next&id=9a1d1e6f926a4d1f4a31a7a37abece9e44455b43

--
Best regards,
Jacek Anaszewski