All of lore.kernel.org
 help / color / mirror / Atom feed
From: benh@kernel.crashing.org (Benjamin Herrenschmidt)
To: linux-arm-kernel@lists.infradead.org
Subject: orion5x and GPIO blink question
Date: Thu, 22 Apr 2010 07:31:13 +1000	[thread overview]
Message-ID: <1271885473.2330.178.camel@pasglop> (raw)
In-Reply-To: <1271870470.1629.85.camel@rex>


> If you have blink enabled/disabled options along with set_brightness you
> can end up in a state where you disable blinking but the brightness the
> LED is left with is effectively random. This is why the LED core does
> things that way and I stand by that as it gives defined behaviour (and
> mirrors the sysfs interface).
> 
> I appreciate in the world of GPIO controllers and the leds-gpio layer
> this is tricky to implement but this is more of a mismatch between the
> GPIO layer and the LED subsystem which was not addressed in the design
> of leds-gpio.

I do agree that it does make some amount of sense from the pure
standpoint of the LED subsystem (and I still somewhat dislike the API
with it's two output parameter function, dunno, somewhat hurts me to see
that in C :-)

You are right in that it's more of a gpio-leds issue. I'll look into
changing the prototype of gpio-leds own set_blink() to sort that out and
fix existing users, maybe this week-end. 

This is not a blocking issue for that dns323 rev C1 support anyways,
just something I noticed in passing, with the current code, the LED is
somewhat hard to be coerced into doing what I want :-)

Cheers,
Ben.

      reply	other threads:[~2010-04-21 21:31 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-21  7:57 orion5x and GPIO blink question Benjamin Herrenschmidt
2010-04-21 14:29 ` Nicolas Pitre
2010-04-21 21:09   ` Benjamin Herrenschmidt
2010-04-21 17:21 ` Richard Purdie
2010-04-21 21:31   ` Benjamin Herrenschmidt [this message]

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=1271885473.2330.178.camel@pasglop \
    --to=benh@kernel.crashing.org \
    --cc=linux-arm-kernel@lists.infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.