linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Pavel Machek <pavel@ucw.cz>
To: Stas Sergeev <stsp@list.ru>
Cc: linux-leds@vger.kernel.org,
	Linux kernel <linux-kernel@vger.kernel.org>,
	Stas Sergeev <stsp@users.sourceforge.net>
Subject: Re: [PATCH v2 0/3] leds: blink resolution improvements
Date: Thu, 30 Apr 2015 19:30:25 +0200	[thread overview]
Message-ID: <20150430173024.GB21211@amd> (raw)
In-Reply-To: <553EA6B9.5040309@list.ru>

Hi!

> >>The following patches improve the precision of led
> >>timer trigger and add the delay unit control.
> >>That allows to make PWM brightness control with timer
> >>trigger.
> >Are you sure that is good idea? Doing LED pwm with main cpu is quite harsh...
> Do you remember the pc-speaker driver? :)

Actually yes, I do, and that one has the same interface as "normal"
sound cards.

> For the timer trigger I would pretty much like my approach to stay.
> The reason is that the PWM I need to do, is not strictly a PWM -
> it needs the ON period in range of tens or hundreds of milliseconds,
> while the OFF period is in a couple of usecs (or vice-versa). No

That is a PWM, right? I see why you'd want to have short "on", but I
don't see why you'd want short "off"...

There's one thing you have to do: having two files, one specifiying
units and second one specifying timeout is not going to work.

What about simply "echo 0.001 > delay_on"?

Thanks,
									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

  reply	other threads:[~2015-04-30 17:30 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-27 17:08 [PATCH v2 0/3] leds: blink resolution improvements Stas Sergeev
2015-04-27 17:09 ` [PATCH 1/3] leds: use hrtimer for blinking Stas Sergeev
2015-04-27 17:11 ` Stas Sergeev
2015-04-27 17:12 ` [PATCH 2/3] ledtrig-timer: add blink delay_unit control Stas Sergeev
2015-04-27 17:14 ` [PATCH 3/3] leds: update documentation about new delay units Stas Sergeev
2015-04-27 20:54 ` [PATCH v2 0/3] leds: blink resolution improvements Pavel Machek
2015-04-27 21:14   ` Stas Sergeev
2015-04-30 17:30     ` Pavel Machek [this message]
2015-04-30 20:42       ` Stas Sergeev
2015-05-03 10:34         ` Pavel Machek
2015-05-03 11:35           ` Stas Sergeev
2015-05-11 22:11             ` Pavel Machek
2015-04-27 22:23   ` Stas Sergeev
2015-04-28  8:57 ` Jacek Anaszewski
2015-04-28 10:12   ` Stas Sergeev
2015-04-28 12:58     ` Jacek Anaszewski
2015-04-28 13:26       ` Stas Sergeev
2015-04-29 15:06         ` Jacek Anaszewski
2015-04-29 11:26       ` Stas Sergeev
2015-04-29 15:14         ` Jacek Anaszewski
2015-04-30 17:11       ` Stas Sergeev
2015-05-04  7:55         ` Jacek Anaszewski
2015-05-04 12:12           ` Stas Sergeev
2015-05-04 15:22             ` Jacek Anaszewski
2015-05-04 17:20               ` Stas Sergeev
2015-05-05  8:22                 ` Jacek Anaszewski
2015-05-05 13:02                   ` Stas Sergeev
2015-05-06  7:20                     ` 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=20150430173024.GB21211@amd \
    --to=pavel@ucw.cz \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-leds@vger.kernel.org \
    --cc=stsp@list.ru \
    --cc=stsp@users.sourceforge.net \
    /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).