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Subject: Re: [PATCH v3 1/2] leds: core: Introduce generic pattern interface
To:     Pavel Machek <pavel@ucw.cz>, Baolin Wang <baolin.wang@linaro.org>
Cc:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Mark Brown <broonie@kernel.org>,
        Linux LED Subsystem <linux-leds@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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 <CAMz4kuKZ6Z1h=yzFYJihEH1ARC5FKtDC6RLz0u8SmaekOZ=utw@mail.gmail.com>
 <20180714212033.GA31950@amd>
From:   Jacek Anaszewski <jacek.anaszewski@gmail.com>
Message-ID: <00fa2693-9308-8d74-0124-04066a76c35a@gmail.com>
Date:   Sun, 15 Jul 2018 00:02:57 +0200
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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

-- 
Best regards,
Jacek Anaszewski