devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jacek Anaszewski <jacek.anaszewski@gmail.com>
To: Christian Mauderer <oss@c-mauderer.de>, Pavel Machek <pavel@ucw.cz>
Cc: linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
	Dan Murphy <dmurphy@ti.com>, Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH v2 2/2] leds: spi-byte: add single byte SPI LED driver
Date: Mon, 6 May 2019 20:34:14 +0200	[thread overview]
Message-ID: <cf99d1f1-4cb2-4e60-3ce1-d123f28536bc@gmail.com> (raw)
In-Reply-To: <911128ec-1327-5895-d101-97801e9c777a@c-mauderer.de>

Hi Christian,

On 5/6/19 10:48 AM, Christian Mauderer wrote:
> On 05/05/2019 22:12, Pavel Machek wrote:
>> Hi!
>>
>>>> +	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
>>>> +	if (!led)
>>>> +		return -ENOMEM;
>>>> +
>>>> +	led->spi = spi;
>>>> +	strlcpy(led->name, name, sizeof(led->name));
>>>> +	mutex_init(&led->mutex);
>>>> +	led->off_value = off_value;
>>>> +	led->max_value = max_value;
>>>> +	led->ldev.name = led->name;
>>>> +	led->ldev.brightness = LED_OFF;
>>>
>>> This line is redundant - already zeroed by kzalloc.
>>
>> Actually I'd prefer to leave it in. Yes, LED_OFF == 0, and will
>> probably stay == 0 in future, but...
>> 									Pavel
>>
> 
> Before I send v4: Currently the initial value isn't written to the LED
> anywhere. The state that is set by U-Boot is just kept till the first
> write to the brightness file.
> 
> I didn't implement "default-state" because the OpenWRT user space sets
> the LED anyway a few seconds later (which is still my use case for that
> driver). But now I noted that there is a remark in the documentation of
> the option "default-state" in devicetree/bindings/leds/common.txt: "The
> default is off if this property is not present."
> 
> Should I send an initial value to the device during initialization or is
> it OK to just keep the original state?

Yes, I would make use of default-state in this case.

-- 
Best regards,
Jacek Anaszewski

  reply	other threads:[~2019-05-06 18:34 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-05 12:52 [PATCH v2 1/2] dt-bindings: leds: Add binding for spi-byte LED oss
2019-05-05 12:52 ` [PATCH v2 2/2] leds: spi-byte: add single byte SPI LED driver oss
2019-05-05 14:48   ` Jacek Anaszewski
2019-05-05 14:55     ` Christian Mauderer
2019-05-05 20:12     ` Pavel Machek
2019-05-06  8:48       ` Christian Mauderer
2019-05-06 18:34         ` Jacek Anaszewski [this message]
2019-05-06 18:19       ` Jacek Anaszewski

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=cf99d1f1-4cb2-4e60-3ce1-d123f28536bc@gmail.com \
    --to=jacek.anaszewski@gmail.com \
    --cc=devicetree@vger.kernel.org \
    --cc=dmurphy@ti.com \
    --cc=linux-leds@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=oss@c-mauderer.de \
    --cc=pavel@ucw.cz \
    --cc=robh+dt@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).