From: Marek Behun <marek.behun@nic.cz>
To: Dan Murphy <dmurphy@ti.com>
Cc: Pavel Machek <pavel@ucw.cz>,
robh+dt@kernel.org, jacek.anaszewski@gmail.com,
linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org
Subject: Re: [RFC PATCH 3/5] documention: leds: Add multicolor class documentation
Date: Tue, 2 Apr 2019 17:56:23 +0200 [thread overview]
Message-ID: <20190402175623.0d85ad7d@nic.cz> (raw)
In-Reply-To: <e2621a54-4c5c-4235-9aba-39a856cfbe88@ti.com>
Hi
On Tue, 2 Apr 2019 06:53:30 -0500
Dan Murphy <dmurphy@ti.com> wrote:
> I agree there are other solutions. Better not so sure.
> We keep kicking a solution down the road we have been talking about adding something to the kernel
> for almost 5 months now, but no one can decide what to do.
>
> How do we move a solution forward?
> Should we just forget the whole idea and keep developing against the current framework?
>
> > One was discussed before -- have single file which contains
> > coefficients for r/g/b channels.
> >
>
> That has been presented as well and the concept was not well received either.
>
> > Or at least... you should not really need separate sync and
> > sync_enable files. One should do.
> >
>
> The idea here was to be able to set the LED brightness immediately on a single LED
> with a single brightness write or setup the color brightness on all the LEDs and then
> sync the LED brightnesses.
>
> If you wanted to control a single LED for notifications the user space may have to do
>
> echo 0 > blue/brightness
> echo 0 > green/brightness
> echo 255 > red/brightness
> echo 1 > sync
>
> As opposed to just
> echo 255 > red/brightness
>
Maybe other kernel developers, or sysfs maintainers like Greg, schould
also have a word about this.
Another solution, although not usable from shell, could be this:
if a process opens all brightness files of a singled multicolor LED
and then does a special SYNC_ON_THIS ioctl on one of them, then the
sync is done when this color is written.
But that would also require ioctl for sysfs files, and I don't think
Greg would like that.
Dan's sync_enable API looks right to me from the one file/one value
sysfs rule as well - you can enable this setting (sync_enable) via one
file.
What is the main reason you guys are concerned about this?
That users will complain that they are writing to red/brightness and
the LED does not change color (because they did not disable
sync_enable)?
Marek
next prev parent reply other threads:[~2019-04-02 15:56 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-01 17:33 [RFC PATCH 0/5] MultiColor LED framework Documentation Dan Murphy
2019-04-01 17:33 ` [RFC PATCH 1/5] leds: multicolor: Add sysfs interface definition Dan Murphy
2019-04-01 17:33 ` [RFC PATCH 2/5] dt: bindings: Add multicolor class dt bindings documention Dan Murphy
2019-04-01 21:29 ` Pavel Machek
2019-04-02 11:40 ` Dan Murphy
2019-04-02 16:17 ` Marek Behun
2019-04-02 17:06 ` Dan Murphy
2019-04-02 20:40 ` Jacek Anaszewski
2019-04-02 19:51 ` Jacek Anaszewski
2019-04-01 17:33 ` [RFC PATCH 3/5] documention: leds: Add multicolor class documentation Dan Murphy
2019-04-01 21:18 ` Randy Dunlap
2019-04-01 21:27 ` Pavel Machek
2019-04-02 5:55 ` Marek Behun
2019-04-02 11:53 ` Dan Murphy
2019-04-02 15:56 ` Marek Behun [this message]
2019-04-01 17:33 ` [RFC PATCH 4/5] dt-bindings: leds: Add LED_COLOR_ID and COLOR_NAME definitions Dan Murphy
2019-04-01 17:34 ` [RFC PATCH 5/5] leds: multicolor: Introduce a multicolor class definition Dan Murphy
2019-04-01 21:10 ` Randy Dunlap
2019-04-02 19:07 ` Dan Murphy
2019-04-02 5:44 ` Marek Behun
2019-04-02 11:55 ` Dan Murphy
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