Linux LED subsystem development
 help / color / mirror / Atom feed
From: Jacek Anaszewski <jacek.anaszewski@gmail.com>
To: Johan Adolfsson <johan.adolfsson@axis.com>,
	Lee Jones <lee@kernel.org>, Pavel Machek <pavel@kernel.org>
Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel@axis.com
Subject: Re: [PATCH RFC] leds: leds-lp50xx: Handle reg to get correct multi_index
Date: Sat, 10 May 2025 17:32:21 +0200	[thread overview]
Message-ID: <62a74e0e-f5a1-40b5-a855-6e9bd620cbd5@gmail.com> (raw)
In-Reply-To: <20250506-led-fix-v1-1-56a39b55a7fc@axis.com>

Hi Johan,

On 5/6/25 12:39, Johan Adolfsson wrote:
> mc_subled used for multi_index needs well defined array indexes,
> to guarantee the desired result, optionally use reg for that.
> 
> If devicetree child nodes is processed in random or reverse order
> you may end up with multi_index "blue green red" instead of the expected
> "red green blue".
> If user space apps uses multi_index to deduce how to control the leds
> they would most likely be broken without this patch if devicetree
> processing is reversed (which it appears to be).

Are you trying to solve some real problem that occurred to you?

The order of DT nodes parsing is not a problem here - we save
color index in subled_info to be able to figure out which color
is on which position. This information can be retrieved in sysfs
by reading multi_index file.

-- 
Best regards,
Jacek Anaszewski

  parent reply	other threads:[~2025-05-10 15:32 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-06 10:39 [PATCH RFC] leds: leds-lp50xx: Handle reg to get correct multi_index Johan Adolfsson
2025-05-08 14:57 ` Lee Jones
2025-05-10 15:32 ` Jacek Anaszewski [this message]
2025-05-12 10:59   ` Johan Adolfsson
2025-05-12 18:10     ` Jacek Anaszewski
2025-05-13 13:04       ` Johan Adolfsson
2025-05-13 19:50         ` Jacek Anaszewski
2025-05-14 14:41           ` Johan Adolfsson
2025-05-13 19:52 ` Jacek Anaszewski
2025-05-14 14:34   ` Johan Adolfsson
2025-05-14 19:55     ` Jacek Anaszewski
2025-05-15  7:36       ` Johan Adolfsson
2025-05-18 15:16         ` 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=62a74e0e-f5a1-40b5-a855-6e9bd620cbd5@gmail.com \
    --to=jacek.anaszewski@gmail.com \
    --cc=johan.adolfsson@axis.com \
    --cc=kernel@axis.com \
    --cc=lee@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-leds@vger.kernel.org \
    --cc=pavel@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