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From: Jacek Anaszewski <jacek.anaszewski@gmail.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: fenglinw@codeaurora.org, linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org, Richard Purdie <rpurdie@rpsys.net>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
	subbaram@quicinc.com, aghayal@qti.qualcomm.com,
	wruan@quicinc.com, kgunda@qti.qualcomm.com
Subject: Re: [PATCH V2 1/2] leds: leds-qti-rgb: Add LED driver for QTI TRI_LED module
Date: Tue, 6 Jun 2017 22:07:18 +0200	[thread overview]
Message-ID: <e4efce59-f611-14e5-1d11-09cb660585b2@gmail.com> (raw)
In-Reply-To: <20170605211609.GA9035@amd>

Hi,

On 06/05/2017 11:16 PM, Pavel Machek wrote:
> Hi!
> 
>> Generally I came to a conclusion that it will be best to register
>> additional LED RGB class device in an addition to three LED class
>> devices representing each color. In order to avoid hard to solve
>> locking problems I propose to allow for simultaneous access to LED
>> class devices and LED RGB class device gathering them.
>>
>> All in all, currently we also don't give an exclusive access to
>> a particular LED class device, which always can lead to overwriting
>> current brightness by another process. These issues must be arbitrated
>> by user space.
>>
>> I propose that LED RGB class device exposed following files:
>>
>> - red_brightness
>> - green_brightness
>> - blue_brightness
>> - latch_color
> 
> Actually, I'd just do single file, "rgb_brightness" with 3
> values. Overhead of writing 3 values is pretty much 0.

You've always been strongly in favor of one-value-per-file
sysfs rule of thumb, but I'm OK with this approach as well :-)

-- 
Best regards,
Jacek Anaszewski

  reply	other threads:[~2017-06-06 20:07 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-01  7:25 [PATCH V2 1/2] leds: leds-qti-rgb: Add LED driver for QTI TRI_LED module fenglinw
2017-06-04 18:33 ` Jacek Anaszewski
     [not found]   ` <8058ed85-5a64-8dc3-99ea-1ad8128e043d-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2017-06-05 21:16     ` Pavel Machek
2017-06-06 20:07       ` Jacek Anaszewski [this message]
2017-06-06 20:13         ` Pavel Machek
     [not found] ` <20170601072723.12760-1-fenglinw-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2017-06-07 22:08   ` Rob Herring

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