Re: [PATCH RFC] leds: Add support for per-LED device triggers

From: Pavel Machek
Date: Mon Jul 13 2020 - 03:12:59 EST


On Mon 2020-07-13 01:18:41, Marek Behun wrote:
> On Mon, 13 Jul 2020 01:15:44 +0200
> Marek Behun <marek.behun@xxxxxx> wrote:
>
> > On Mon, 13 Jul 2020 00:38:21 +0200
> > OndÅej Jirman <megous@xxxxxxxxxx> wrote:
> >
> > > So after trying to use this, this seems to disallow the use of multiple HW
> > > triggers per LED. That's fine by me, because using one HW sysfs configured
> > > trigger per LED that use case is my proposal, but is it desireable in general?
> >
> > Why? If you register one LED and several triggers, all sharing the same
> > trigger_type pointer, I think it should work.
> >
> > Marek
>
> The problem arises when I have two LEDs and two HW triggers, and the
> hardware allows setting one HW trigger on both LEDs and other HW
> trigger only on one LED. But this could simply be ignored - the
> set_trigger function could simply return -ENOTSUPP or something.

In this case you should have two trigger_type pointers (since two LEDs
are different), and yes, you'll have duplication for one of the
triggers. I don't think thats a problem.

Best regards,

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

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