Re: [PATCH v3 1/2] leds: core: Introduce generic pattern interface

[Jacek Anaszewski]

On 07/15/2018 12:39 AM, Pavel Machek wrote:
> On Sun 2018-07-15 00:29:25, Pavel Machek wrote:
> > On Sun 2018-07-15 00:02:57, Jacek Anaszewski wrote:
> > > Hi Pavel,
> > >
> > > On 07/14/2018 11:20 PM, Pavel Machek wrote:
> > > > Hi!
> > > >
> > > > > > It also drew my attention to the issue of desired pattern sysfs
> > > > > > interface semantics on uninitialized pattern. In your implementation
> > > > > > user seems to be unable to determine if the pattern is activated
> > > > > > or not. We should define the semantics for this use case and
> > > > > > describe it in the documentation. Possibly pattern could
> > > > > > return alone new line character then.
> > > >
> > > > Let me take a step back: we have triggers.. like LED blinking.
> > > >
> > > > How is that going to interact with patterns? We probably want the
> > > > patterns to be ignored in that case...?
> > > >
> > > > Which suggest to me that we should treat patterns as a trigger. I
> > > > believe we do something similar with blinking already.
> > > >
> > > > Then it is easy to determine if pattern is active, and pattern
> > > > vs. trigger issue is solved automatically.
> > >
> > > I'm all for it. I proposed this approach during the previous
> > > discussions related to possible pattern interface implementations,
> > > but you seemed not to be so enthusiastic in [0].
> > >
> > > [0] https://lkml.org/lkml/2017/4/7/350
> >
> > Hmm. Reading my own email now, I can't decipher it.
> >
> > I believe I meant "changing patterns from kernel in response to events
> > is probably overkill"... or something like that.
>
> Anyway -- to clean up the confusion -- I'd like to see
>
> echo pattern > trigger
> echo "1 2 3 4 5 6 7 8" > somewhere

s/somewhere/pattern/

pattern trigger should create "pattern" file similarly how ledtrig-timer
creates delay_{on|off} files.

--
Best regards,
Jacek Anaszewski